NorthStar 958 Operator's Manual

NORTHSTAR

958 Integrated

Navigation System

Operator’s Manual

P/N GM958UM Revision A

Limited warranty policy

Northstar Technologies, Inc. warrants the Northstar 958 to be free from defects in materials and workmanship for a period of two (2) years. This warranty applies to the original purchaser and to any subsequent owner during the warranty period, which begins on the date of shipment of the 958, F.O.B. Acton, Massachusetts, to an authorized Northstar dealer.

Systems may not be returned to Northstar without a Returned Materials Authorization

(RMA) number. Call your Northstar dealer or Northstar for instructions.

During the 958’s warranty period, Northstar will repair or replace, at its option, any part of the 958 it finds to be defective due to faulty material(s) or workmanship. All such repairs and/or replacements will be promptly performed by Northstar free-of-charge to the owner, excluding freight costs incurred in shipping to the factory. Return shipments from Northstar to points within the United States are made via ground transportation, freight prepaid.

Special shipping charges (overnight, two-day, and so on) are the responsibility of the owner.

To be covered by this warranty, the Northstar equipment must have been in normal use.

This warranty does not apply to 958’s with defects caused by improper installation, physical damage, abuse, tampering, lightning or other abnormal electrical discharge, or to

958’s with defaced or altered serial numbers, or to 958’s repaired by unauthorized persons or repaired in a manner that violates Northstar’s recommended service procedures.

All repairs and/or replacements made under this warranty must be performed at Northstar’s facilities in Acton, Massachusetts. Performance of warranty work elsewhere will not be authorized, and Northstar will not pay for any charges for such work. Northstar will not be responsible for payment of any charges imposed by a Northstar dealer or other party for services requested by and/or performed for a 958’s owner in connection with this warranty. Such services might include removal of the 958 from a vessel, inspection, packaging, handling, reinstallation, and the like.

Northstar Technologies assumes no responsibility for any consequential losses of any nature with respect to any of its products or services sold, rendered, or delivered. The foregoing is the only warranty expressed or implied. No other warranty exists.

CAUTION!

Northstar products are designed to be very useful navigation tools, but they are not substitutes for good seamanship. The prudent navigator should never rely on any single device as the sole source of navigation guidance. Exercise caution and good judgment when underway.

CAUTION!

The electronic chart is an aid to navigation designed to facilitate the use of authorized government charts, not replace them. Only official government charts and notices to mariners contain all the information needed for safe navigation, and, as always, the user is responsible for their prudent use.

Contents

1 Getting Started . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Welcome to the 958 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Using this manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Obtaining technical support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Turning the 958 on and off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Displaying the chart screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Using chart data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Displaying detailed position information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Using demo mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Going to a quick waypoint now . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

2 Introducing the 958 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Introducing the controls. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Introducing the display screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Introducing radar. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Introducing the echo sounder. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Introducing alarms, TideTrack, and video . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Maintaining the 958 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Interfacing the 958 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

3 Using the Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Using the PWR key . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Using the five function keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Using the CURSOR PAD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Using the SAVE key . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Using the MOB key . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Using the alphanumeric KEYPAD. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Using the menu keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Using the BRIGHTNESS key. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Using the IN and OUT keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

4 Using the Chart Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Understanding electronic charts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Understanding nav aids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Zooming in and out. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Controlling the cursor on the chart screen. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Comparing vessel and browse modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

958 Operator’s Manual, Rev. A Page i

Splitting the screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Controlling the screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Rotating the chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Setting up the chart screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Using distance and bearing mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

5 Determining Your Position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Displaying position, COG, and speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Using GPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Using DGPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

Using loran . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

Using Phantom Loran . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

6 Understanding the Waypoints Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

Introducing waypoints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

Displaying waypoints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

Displaying waypoint coordinates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

Creating new waypoints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

Creating avoidance-area waypoints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

Editing waypoints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

Updating waypoint coordinates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

Moving waypoints/routes between units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

Transferring waypoints to and from a PC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

7 Understanding the Routes Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

Introducing routes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94

Creating routes from the chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95

Creating routes from a waypoints list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

Saving a route as you travel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

Editing a route . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100

8 Understanding Waypoint/Route Navigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .109

Navigating to waypoints. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110

Steering to a waypoint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112

Navigating along routes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116

Restarting the course line. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118

9 Using the Nav Log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .121

Introducing the nav log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122

Changing your trip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123

Stopping and restarting navigation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124

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10 Understanding Radar Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .125

Understanding how radar works. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126

Displaying and controlling radar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126

Turning radar on and off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128

Overlaying radar on the chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128

Changing scale and rotation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130

Using the main radar keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132

Using the adjust radar keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134

Using the radar markers keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137

11 Alarms, TideTrack, and Video Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .143

Understanding alarms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144

Understanding TideTrack™ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158

Using the video display option . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160

12 Setting Up Your 958 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .163

Changing your display settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164

Changing your navigation settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167

Changing your receiver settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172

Changing your port settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177

Setting up the sounder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177

Setting up radar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177

Installing Software Updates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178

Displaying manufacturer’s information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178

Changing the time zone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182

Appendix A - Understanding GPS, WAAS, and Radar . . . . . . . . . . . . . . . . . . . . . . . . .183

Introducing GPS and WAAS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183

Introducing radar. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187

Appendix B - System Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .191

Appendix C - Geodetic Datums . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .197

Appendix D - Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .205

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .211

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Page iv 958 Operator’s Manual, Rev. A

958 Operator’s Manual, Rev. A

1

Getting Started

Welcome to the 958 . . . . . . . . . . . . . . . . . . . . . . . . . 2

Using this manual . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Obtaining technical support . . . . . . . . . . . . . . . . . 3

Turning the 958 on and off . . . . . . . . . . . . . . . . . . 5

Displaying the chart screen . . . . . . . . . . . . . . . . . . 7

Using chart data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Displaying detailed position information . . . 13

Using demo mode . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Going to a quick waypoint now . . . . . . . . . . . . . 16

T his chapter introduces this manual, familiarizes you with the 958’s navigation functions and CHART screen features, and explains how to display basic positioning information on the CHART screen.

Page 1

Chapter 1 - Getting Started

Welcome to the 958

Congratulations on your purchase of the Northstar 958

Integrated Naviagation System! The 958 is a full-featured color

GPS/vector charting system, which is extremely easy to use, but meets your marine navigation needs in a comprehensive, logical manner. The 958 has several requirements that must be met to ensure safe and proper operation. To ensure that all critical installation parameters are met, installation and interfacing of the 958 should be handled by a marine technician using the guidelines found in the Northstar 958 Installation

Manual .

The 958 combines GPS with WAAS or optional radiobeacon differential position navigation, and offers a high-resolution

10.4” full-color screen, Navionics cartography, radar, a video overlay feature, optional fish finding capability using

Northstar’s add-on echo sounder (fishfinder), and many other features.

The 958 anticipates your most common requests for navigation information, so accessing most functions requires just one or two keypresses. By reducing the attention required to navigate, you can devote more time to other aspects of your trip.

For information on installing, interfacing, and troubleshooting the 958, please see the Northstar 958 Installation Manual (part number GM958IM) or contact your local authorized Northstar dealer.

Using this manual

This manual complements the 958’s ease-of-use by describing and illustrating its various functions in a format that’s conducive to fast learning and safe operation.

The manual’s sections are grouped by related functions, starting with an overview of the basic control-panel layout and function commands, and moving to more advanced waypoint and route navigation operations. Sample screens are provided to show how each function appears on the 958’s display screen.

Once you start using the 958, you’ll discover that you can use it without constantly referring to this manual. After you’ve read the manual once, you probably won't have to refer to it very often.

Page 2 958 Operator’s Manual, Rev. A


Conventions

This manual uses certain conventions to provide a consistent way to recognize specific information, as follows:

• is the universal caution symbol for caution and warning information related to your personal safety or possible damage to the system. The

CAUTION

and

WARNING

boxes contain critical information—please read them!

•

•

NOTE

is the type style used for titles of notes. These notes contain valuable information that’s purposely highlighted so you won’t miss it while reading the main text.

• KEY is the type style used to refer to the function keys

(the five main keys located below the left side of the display screen) as well as the six menu keys (located in a vertical row on the right side of the 958).

• DISPLAY TEXT is the type style used for text that appears on the display screens.

• Sample 958 screen is the type style used for captions of display screens.

Figure 1

is the type style used for captions of figures.

• A bulleted list contains a series of related items or topics.

• A numbered list contains a series of steps in a procedure.

• The command “Press a button or key” means push briefly and release, unless otherwise specified.

• Latitude and longitude coordinates are collectively referred to as lat/lon coordinates or just lat/lon.

Obtaining technical support

After you’ve follow the instructions in this manual, if you need technical support or have any other questions, you can contact Northstar by email, fax, phone, or U.S. mail as follows:

Table 1: Contacting Northstar

Email :

Service: [email protected]

Sales: [email protected]

958 Operator’s Manual, Rev. A Page 3


Table 1: Contacting Northstar (continued)

Fax :

Service: 978/897-1595

Sales: 978/897-7241

Telephone:

Main number: 978/897-6600 or 800/628-4487

U.S. mail:

30 Sudbury Road

Acton, MA 01720 USA

Website: www.northstarcmc.com (you can send email to

Northstar from this site).

Hearing from you

Your feedback is important and helps Northstar ensure that this manual is a valuable resource for all 958 users. Send your questions, comments, or suggestions about this manual to:

[email protected]

Service and repair

In case of a 958 operating problem, you can contact your dealer or return the 958 to Northstar for diagnosis and repair.

Before returning the 958 for repair, you may want to save your waypoints and routes. When describing an operating problem, be as complete and accurate as possible. Be sure to have your

958’s serial number and software revision available whenever contacting or corresponding with your dealer or Northstar .

If you need help, call the Northstar Service Department at

978-897-6600.

NOTE:

To prevent delays, it’s critical that you first obtain a Return Materials

Authorization (RMA) number from the Service Department before returning your 958 to Northstar.

The 958 is covered by a two-year limited warranty (see the

Limited Warranty Policy at the front of this manual), which, in summary, states that if the 958 is returned to Northstar by the owner or dealer during the warranty period, Northstar will


Chapter 1 - Getting Started repair or replace, free of charge, any part found to be defective due to faulty materials or workmanship, if the 958 has been properly installed and hasn’t been abused. The only cost to the owner will be the one-way shipping charges and any associated charges that may be imposed by the dealer.

Shipments to Northstar should be made to the following address:

Northstar Technologies

30 Sudbury Road

Acton, MA 01720

If you have special overnight or second-day shipping requirements (UPS or Federal Express), please call Northstar for turnaround time and freight costs before you ship your

958.

For details about service procedures, see the Limited Warranty

Policy in this manual.

Turning the 958 on and off

Turning the 958 on

To turn the 958 on, briefly press the PWR key. The 958 emits several short beeps as it displays the START-UP screen, then the 958 performs a series of self-tests to check its critical components and functions.



After the 958 displays its START-UP and SELF-TEST screens, a message is shown to warn you against relying on the 958’s chart cartography as the only means of safe navigation.

Page 6

CAUTION!

Be extremely careful when navigating with electronic charts.

Although every effort has been made to ensure that the data the 958 uses is as close as possible to paper charts, errors and omissions are inevitable. The captain is responsible for cross-checking the 958 against other sources of navigation data.

To continue, accept the WARNING MESSAGE by pressing any one of the five function keys ( CHART , STAR , STEER , NAV

LOG , or WAYPTS/ROUTES ) located below the display screen.

A 958 that has recently been used at or near that same location will usually be ready to navigate within one minute.

Now you’re ready to get underway with your 958!


Checking GPS and

WAAS status


Once the 958 is on and has acquired its satellite data, you can always check the quality of the GPS signals by viewing the various satellites’ SNR reading (Signal-to-Noise Ratio) as described in see ”Viewing GPS satellite status” starting on page

62.

Turning the radar on

If you have radar installed and connected to Port 2, it won’t be operational until you turn on the radar transmitter. See

”Turning radar on and off” beginning on page 128.

Turning the 958 off

To turn the 958 off, press and hold the PWR key for a few seconds until the screen goes dark.

Displaying the chart screen

Displaying your vessel’s present position

After the 958 successfully completes its start-up sequence, press the CHART function key to display the CHART screen.

You’ll see your present position represented by a black triangular vessel symbol in the center of the chart. The DGPS or WAAS indicator on the right side of the screen means the

958 is currently receiving radiobeacon (optional) or WAAS signals. White areas are water and brown areas are land. If you’re using a chart cartridge, nav aids and depth contours are shown as well as landmark names.



If your vessel is moving, the symbol will point in the direction of your course over ground. This direction may be different from your heading. The vessel symbol shows your actual direction of travel over the bottom, not the direction you’re headed. If your vessel isn’t moving, the 958 can’t determine your COG, so the direction of the vessel symbol won’t mean anything.

The scale of your first view is about 128 nautical miles (nm) from edge to edge. To see more details about your position, press the IN key. To see more area and less detail, press the

OUT key.

Rotating the chart

To change the chart-viewing angle from north-up to course-up to heading-up to leg-up, cycle through the choices by pressing the ROTATE key.

The current angle is shown at the bottom half of the key.

Displaying other information

You can set up your 958’s CHART screen to display your current route, your track history, nearby waypoints or avoidance points, a lat/lon grid, a radar overlay, or other chart details. For details, see see ”Setting up the chart screen” starting on page 53.

Clearing a GPS or

WAAS alarm

If the 958 doesn’t acquire GPS or WAAS signals within two minutes, you’ll see a flashing NO GPS alarm icon on the lower right side of the screen. This means the 958 has an alarm message that needs your acknowledgement: Press the STAR function key (twice if the echo sounder is installed) to display the ALARMS screen.



The alarm message NO GPS POSITION FIX is shown in the

RECENT ALARMS box. This message is a normal part of using a

958 for the first time, and advises you that the 958 is acquiring the necessary satellite information. This situation usually occurs in a 958 that’s been shipped more than several hundred miles from Northstar, and often just the first time the

958 is turned on. This first time, the 958 takes two to five minutes to acquire the necessary information, and after that, is ready to navigate.

The word NEW in the upper right corner tells you this message hasn’t already been acknowledged. To acknowledge, press the

CLEAR ALARM menu key. As soon as the 958 acquires its signals, you’ll be ready to go.

For details about alarms, see ”Using the alarms” starting on page 25, and see ”Understanding alarms” starting on page 144.

Using chart data

You have two choices for viewing chart data:

•

• use the 958’s built-in Navionics worldwide maps use Navionics’ chart-data cartridges

The 958 contains a built-in, low-resolution map that covers the entire world at a fairly low level of detail. This large-scale set of


Chapter 1 - Getting Started maps can give you an approximate idea of your location with respect to land areas. Nav aids are not included.

For more detailed charting data, you’ll want to use Navionics’ highly detailed miniature Nav-Chart™ cartridges. Navionics is a major producer of high-quality, high-resolution “seamless” digital charts. The 958’s usefulness is greatly enhanced with cartridges for the areas to which you plan to navigate.

Cartridge data is the result of countless hours of converting land-mass shapes, nav-aid names and locations, depth contours and other information found on official paper charts into an electronic format used by the 958. Each cartridge includes several charts covering a specific geographic location, typically providing zoom in and out levels ranging from a maximum detail of 1/4 nm across the screen to an overview of up to 256 nm across. Virtually every major port and most popular boating areas are available on these cartridges, and new charts are constantly being added. For details about obtaining Navionics charts, contact your authorized Northstar dealer.

Inserting a chart cartridge

The cartridge slot is located at the lower left-hand corner of the 958. You can see if a cartridge is inside by opening the cartridge access door and looking inside the slot. If the 958 is on, press the CHART SETUP menu key to the right of the

CHART screen to display the CHART STATUS screen (the cartridge door must be fully closed and latched to display this information):

• If a cartridge is inside, the cartridge name and date are shown at the left of the CHART SETUP/STATUS screen

(screen at left, below).




• If a cartridge isn’t installed or is installed incorrectly, the words NONE INSERTED are shown (screen at right, below).

NONE

INSERTED

The cartridge name comes from its Navionics catalog number.

Not all cartridges will have a date, especially older ones; in this case, only the word PRESENT is shown rather than the name and date.

Before you insert the cartridge, make sure the cartridge label is facing up and the cartridge is oriented as shown in Figure 1:

”Properly inserting a chart cartridge,” below. Insert the cartridge gently but firmly into position with one straight, smooth motion. If you only partially insert the cartridge, stop, then move the cartridge again, it may get stuck in an awkward position.

Page 11


The Navionics chart cartridge must remain free from debris and moisture at all times. To ensure that you do not expose the cartridge to any environmental damage, please use caution when changing the cartridge. Be careful when inserting the cartridge into the

958 (see description and illustration at right). When you’re not using the cartridge, store it in a clean, dry place away from heat, humidity, and dust.

Improper handling and storage of the cartridge may damage the Northstar 958. Such damage is not covered under the 958 warranty.

Figure 1: Properly inserting a chart cartridge



Displaying detailed position information

You can display detailed position information on two screens:

•

• the CHART screen the GPS POSITION screen

To display position information on the CHART screen, press the MORE INFO menu key to display an “info bar” at the bottom of the screen.


Each additional press of the MORE INFO key shows the following information:

•

• your vessel’s present Speed-Over-Ground ( SOG ),

Course-Over-Ground (COG) , and heading your vessel’s distance ( DIST ) and bearing (BRG) to the current waypoint, if any

• your vessel’s position in lat/lon (or TDs, if enabled)

• the depth, water temperature, and Speed-Through-Water

(STW) as measured by the echo sounder

To display position information on the GPS POSITION screen, press the CHART function key again to display the GPS

POSITION screen.

Page 13


The GPS POSITION screen shows the following information:

•

•

•

• your vessel’s position in lat/lon (or TDs, if enabled) your vessel’s present SOG and current time, day, and date

COG geodetic datum (for details, see ”Appendix C - Geodetic

Datums” starting on page 197)

For details about determining and displaying your position, see ”Determining Your Position” starting on page 59.

Using demo mode

You can use demo mode to simulate a stationary position, or simulate going to a cursor location on the CHART screen.

To access demo mode, on the CHART screen, press the CHART

SETUP key, then press the DEMO CONTROL key to display the DEMO CHART screen.




To move your vessel to a simulated position, press the

CURSOR PAD to move the cursor to the desired position and press the DEMO POSITION key. To start demo mode at this new position, press the ENTER key. Your vessel symbol will now be stationary at this position.

To travel from here to a new cursor location, press the

CURSOR PAD to move the cursor to the desired position, then press the DEMO COG/SOG key. To set your vessel’s speed, use the KEYPAD to enter the desired speed, then press the ENTER key to start going to the demo cursor location.

To go back to the CHART screen (but stay in demo mode), press the RETURN key twice. The word DEMO always appears on the CHART screen when you’re in demo mode.

To exit demo mode, on the DEMO CHART screen, press the

EXIT DEMO key. This immediately returns you to the CHART screen.

NOTE:

Video image display, simulated radar image, chart rotation, and zooming in and out all work normally on the DEMO CHART screen.

Page 15


Going to a quick waypoint now

You can point to any location on the CHART screen and go right to it. This is called “point-and-shoot” navigation, which can be the easiest and most powerful way to go to a waypoint:

Just select different locations and go to them, one at a time, right on the chart. This way of navigating provides the most flexibility in deciding where you want to travel. Simply move the cursor wherever you want, press a key, and you’re navigating.

1. Press the CHART function key to display the CHART screen.

2. Move the cursor to the desired chart location by pressing the CURSOR PAD in the lower right corner of the 958.

3. Press the GO TO CURSOR menu key at the lower right of the screen.

Page 16

4. When prompted with the message START NAVIGATING

TO CURSOR POSITION , press the ENTER key.




The 958 displays a track line to the new waypoint named

QUIK, and guides you directly to this point.

That’s all you have to do to use the 958 in its simplest form. To learn more about navigating to waypoints, see

”Navigating to waypoints” starting on page 110.

Page 17




2

Introducing the 958

Introducing the controls . . . . . . . . . . . . . . . . . . . . 20

Introducing the display screen . . . . . . . . . . . . . . 21

Introducing radar . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Introducing the echo sounder . . . . . . . . . . . . . . 25

Introducing alarms, TideTrack, and video . . . 25

Maintaining the 958 . . . . . . . . . . . . . . . . . . . . . . . . 26

Interfacing the 958 . . . . . . . . . . . . . . . . . . . . . . . . . 28

T his chapter introduces you to the 958’s features, functions, and display modes.

Page 19

Chapter 2 - Introducing the 958

Introducing the controls

Figure 2 below illustrates the functions of the 958’s controls.

Feel free to try any of the 958’s controls! You can’t hurt anything, and can only learn more about how to use the 958 more efficiently. The 958 always asks you to verify what you’re doing when changing or deleting information. You’ll be asked to confirm your action before anything happens that may affect the 958’s operation. You can always cancel a function at the last second.

For details about each of these controls, see ”Using the

Controls” starting on page 29.

NORTHSTAR

957

Page 20

Figure 2: 958 controls



Introducing the display screen

Overhead view

The 958’s CHART screen displays navigation data in an easily recognizable, practical format: an overhead view of your vessel’s present position (or any position you choose) in relation to land masses, nav aids, and your own defined waypoints and routes. As you navigate, your vessel remains centered on the CHART screen, and the chart moves underneath your vessel.

Chart screen redraw feature

The CHART screen’s high-speed redraw feature means you don’t have to wait when you’re scrolling from one location to the next. The 958 automatically keeps the chart visible—even as you move from one chart to the next. Move the cursor, press a key, and you’re still navigating through a channel, around an island, or in open water—always in full view of what’s around you at all times.

Occasionally, you may see an hourglass symbol briefly displayed on the screen while the 958 is changing or redrawing the chart.

Split screen/overlay feature

If your 958 is equipped with radar and/or echo sounder, you can split the screen to show the chart, radar, and sounder together in various combinations. In addition, you can overlay a radar image on the chart and/or overlay a video image on most screens. An introduction to these functions is given later in this chapter. For details about the split screen, see ”Splitting the screen” starting on page 46.

Display-screen lighting

The 958’s large full-color screen is easily readable under all conditions from full, direct sunlight to total darkness.

Anti-reflection treatment of the display and its window eliminates over 90 percent of the reflection and glare usually encountered in bright sunlight.



Adjusting the brightness

The fluorescent tubes that illuminate the 958 slowly dim after several thousand hours of use. If you use your 958 for many hours each day, you may want to keep the level of the display lighting low when you don’t really need it. To adjust the screen’s brightness, press the BRIGHTNESS key: Pressing the upper arrow brightens the screen; pressing the lower arrow darkens it.

Chart plotter function

The 958 plots your position on the CHART screen. Nearby land masses, depth contours, nav aids, waypoints, avoidance areas, and a lat/lon grid may be displayed, along with your vessel’s image. When you’re using the 958 as a chart plotter, the menu keys to the right of the display screen let you perform the following functions:

•

•

•

• restart the desired track line to run directly from your position to the waypoint, “zeroing” the cross-track error display change the options available for the CHART screen display additional position information in the INFO BAR at the bottom of the screen go to a waypoint, nav aid, or unmarked point you select on the CHART screen by pressing the CURSOR PAD

Auto-dimming

When the display screen is at full brightness, if the 958 becomes too hot inside due to the outside temperature and sunlight, the display screen will automatically dim.

Auto-dimming helps maintain the integrity of the display and reduce power consumption when the 958 is on and running too hot for its current environment. You can override the auto-dim function at any time by increasing the brightness with the BRIGHTNESS key. The 958 may dim again as required so as not to exceed the maximum internal temperature.


Special display windows


Occasionally, the 958 needs to tell you something or ask permission to do something. When this happens, a special information or question window appears on the display. This window may contain an alarm icon, or an INFO label or a large question mark along with a message for you to read.

Flashing alarm icons

The 958 communicates alarm messages by flashing an alarm icon on the bottom right side of the screen. Alarm messages contain information you may want to read as soon as possible.

To see the alarm condition on the ALARMS screen, press the

STAR function key (twice if the echo sounder is enabled).

Messages you haven’t seen already display the word NEW in the upper right corner. To turn off the flashing icon and remove the message, press the CLEAR ALARM menu key.


Info windows

The 958 displays info windows while you’re entering data or using control functions. These windows give extra details about what’s going to happen, or let you acknowledge a command. Info windows always appear with the word INFO in a small box.

Page 23


Question windows

A question window appears when the 958 needs a response from you. You must respond to any question window by pressing the ENTER key to answer yes, or the CLEAR key to answer no. Most of the other keys, including the function keys as well as the video image display, are temporarily inactive while the 958 displays a question window.



Introducing radar

With radar, you can determine where other boats or ships, navigational markers, land masses, flocks of birds, and other objects are located in relation to your vessel, and you can track their movements.

You can display radar by itself or in combination with the chart and sounder. You can also overlay the radar image on the CHART screen. For details about radar functions, see

”Understanding Radar Functions” starting on page 125.

For information about the radar setup, see ”Setting up radar” starting on page 177. For information on installing radar and making it operational, see the Northstar Radar Installation

Manual (part number GMRadarIM).

Introducing the echo sounder

If your 958 is equipped with Northstar’s optional sounder, pressing the STAR key will display the full ECHO SOUNDER screen. You can also display the ECHO SOUNDER screen in various combinations with other screens.

For information about viewing the sounder in combination with other screens, see ”Splitting the screen” starting on page

46. For information about the sounder setup, see ”Setting up the sounder” starting on page 177. For details about using (and installing) the sounder, see the Northstar 490 Operator’s

Manual (part number GM490).

Introducing alarms, TideTrack, and video

The 958 has several special functions:

•

•

• alarms

TideTrack display video image display

Using the alarms

The 958 has several alarms that automatically alert you to certain situations. For example, when you’re approaching a waypoint, the 958 lets you know by sounding a beep and


Chapter 2 - Introducing the 958 flashing an alarm icon on the screen. The 958 offers four adjustable alarms, including anchor, cross-track distance, arrival radius, and DGPS time-out. For details, see

”Understanding alarms” starting on page 144.

Using TideTrack™

The 958’s TIDE TRACK screen displays a 24-hour tide graph for any of over 3,000 NOAA tide stations covering the entire

U.S. coastline, including Alaska and Hawaii, plus much of the eastern and western Canadian coastline. You can display tides for the current date or any other date. For details about

TideTrack, see ”Understanding TideTrack™” starting on page

158.

Using the video image overlay

The 958 offers a video display feature that lets you overlay an image from a connected video source onto most of the 958’s display screens. You can also easily adjust the size, position, and transparency of the image (that is, how much of the underlying screen you can see through the video image). For details, see ”Using the video display option” starting on page

160.

Maintaining the 958

Basic maintenance

To help retain the 958’s best possible performance, Northstar recommends following these suggestions:

•

•

•

•

• keep the cartridge access door closed at all times, unless inserting or removing a chart cartridge, to prevent moisture and dirt from entering the 958 don’t change the cartridge when the 958 is exposed to water spray, rain, or moisture of any kind keep spare cartridges in a safe, watertight place where they can’t be misplaced keep fingerprints off the display screen (remove any prints with a lens cleaning cloth) remove dirt and grime with Windex and a soft cloth, or else soap and water



•

•

• don’t scratch the display by scraping a sandy or salty cloth across it use the 958’s protective plastic cover when not in use don’t open the 958’s case—there aren’t any user-serviceable parts inside

Cleaning the display screen

Pre-packaged moist towellettes (especially those containing a small amount of alcohol) are excellent for cleaning the 958’s display window. You might want to keep a supply on hand to wipe off fingerprints and other smudges.

Be careful when cleaning the glass window covering the display screen. Although the window is scratch-resistant, you may damage the anti-reflective coating if you use a dry cloth to wipe dirt off. When wiping the window, always use a damp cloth or a clean and dry microfiber-type lens cleaning cloth. To dissolve any oil or grease on the screen, use a small amount of window cleaner or alcohol.

If possible, try not to touch the window with your fingers. The natural oils from your hand will temporarily affect the characteristics of the screen and cause your fingerprints to appear as bright reflections. These will disappear, however, when you clean the screen as described above.

Protecting the 958

Excessive heat can cause short- and long-term damage to the

958. Although the 958 can recover from short-term effects, long-term damage may be permanent. When the 958 is out in the hot sun, but isn’t being used, always use the protective plastic cover.

If left disconnected and exposed, the 958’s rear connectors may corrode slightly from exposure to saltwater spray. If the connectors are not in use, always keep their plastic caps on.

Protect the entire 958 from prolonged exposure to the elements by mounting it, if possible, in a relatively dry location. At the end of a trip, wipe the 958 dry.



Interfacing the 958

The 958 can be connected to a wide variety of compatible marine devices, including the Northstar 490 that adds complete fishfinding capability to the 958. This type of connection should be done by a qualified marine electronics technician. For details, contact your local authorized Northstar dealer.



3

Using the Controls

Using the PWR key . . . . . . . . . . . . . . . . . . . . . . . . . 30

Using the five function keys . . . . . . . . . . . . . . . . 30

Using the CURSOR PAD . . . . . . . . . . . . . . . . . . . . . 32

Using the SAVE key . . . . . . . . . . . . . . . . . . . . . . . . . 33

Using the MOB key . . . . . . . . . . . . . . . . . . . . . . . . . 33

Using the alphanumeric KEYPAD . . . . . . . . . . . 34

Using the menu keys . . . . . . . . . . . . . . . . . . . . . . . 35

Using the BRIGHTNESS key . . . . . . . . . . . . . . . . . 36

Using the IN and OUT keys . . . . . . . . . . . . . . . . . 36

T his chapter explains how to use all of the various controls to operate the 958.

Page 29

Chapter 3 - Using the Controls

Using the PWR key

To turn the 958 on, briefly press the PWR key. The 958 emits several short beeps as it first displays the STARTUP screen, followed by the SELF-TEST screen. This screen displays the results of the 958’s self-tests, which are automatically run each time you turn power on. After you clear the WARNING

MESSAGE , the 958 will display navigational data.

To turn the 958 off, press and hold the PWR key for several seconds until the screen goes dark.

Using the five function keys

The five function keys— CHART , STEER , WAYPTS/ROUTES ,

STAR , and NAV LOG —located across the lower left part of the

958, control the functions you’ll use most often. You can press any function key, at any time, on any screen, to display the information you need.

CHART function key

The CHART key displays your position on the CHART screen

(shows lat/lon graphically) or on the GPS POSITION screen

“Where am

(shows lat/lon numerically). Both screens also display COG

I?” and SOG.

You can display position as any of the following:

>

>

>

> as GPS/WAAS or DGPS lat/lon coordinates as lat/lon from an external loran receiver (if connected) as loran TDs (if you’ve connected a loran to the 958) as Phantom Loran TDs (by converting GPS coordinates to Loran TD’s)

STEER function key

The STEER key shows you how to steer precisely along a course line to a designated waypoint. Your position is shown

“How do I get in relation to your course line, and numerical information is to my shown to help you steer directly to your waypoint, including waypoint?” cross track error, distance and bearing, estimated time to waypoint, estimated time of arrival, COG and SOG, and speed of advance.



There are two versions of the steer display: traditional

STEERING and 3D STEER . Press the STEER function key once to see the version you last used. Press it again to see the other one.

For details, see ”Steering to a waypoint” starting on page 112.

STAR function key

The STAR key lets you:

• display the optional ECHO SOUNDER screen (this requires the optional Northstar echo sounder; see the Northstar

490 Operator’s Manual , part number GM490, for details on sounder setup and operations)

•

• display an explanation of alarms and any messages the

958 has for you, and set the alarms that are adjustable display the VIDEO SETUP screen, where you enable the video image and adjust its size and placement on the display screen

• display graphical TideTrack information at over 3,000

NOAA tide stations

• display the time, day, and date, and the time of today’s sunrise and sunset

• display screens that lets you set up the 958 according to your specific needs

For details about alarms, TideTrack, and video, see ”Alarms,

TideTrack, and Video Display” starting on page 143. For details about setting up your 958, see ”Setting Up Your 958” starting on page 163.

WAYPTS/ROUTES function key

“Where do I want to go?”

The WAYPTS/ROUTES key lets you:

•

•

• create new waypoints and routes display a list of previously stored waypoints and routes choose where you want to navigate

For details, see ”Understanding the Waypoints Function” starting on page 71, and see ”Understanding the Routes

Function” starting on page 93.



NAV LOG function key

“How am I doing?”

The NAV LOG key displays a list of the waypoints you’ve passed, lets you change those ahead of you, reverse the direction of your trip, and stop or restart navigation. For details, see ”Using the Nav Log” starting on page 121.

Using the CURSOR PAD

Pressing the large CURSOR PAD — located in the lower right corner of the 958 — while you’re displaying the CHART screen will move the cursor across the CHART screen in an up and down, left to right, or diagonal direction. To move the cursor diagonally, press the CURSOR PAD between any two of its arrows.

Pressing the CURSOR PAD while displaying text screens will move the flashing cursor to the data you want to either display or change. For example, when you’re entering such data as the name of a waypoint, or its coordinates, press the CURSOR

PAD down to move the cursor down to a particular area of data, then press the CURSOR PAD right to move the cursor to a particular character in that area.

The cursor itself may be hard to see when it’s located in a busy section of the CHART screen. To help you, the 958 displays four small red cursor pointers in the middle of each side of the screen (see below) that match and follow the cursor’s position.

You can always rely on these pointers to show you the cursor.



Cursor pointers

Using the SAVE key

The SAVE key instantly saves your vessel’s position as a waypoint—at any time, on any screen, during any function.

Press the SAVE key to store your position. This new waypoint is automatically given a name, such as S001, where the letter

S indicates a saved waypoint and the three-digit number increases by one ( -S002, -S003, etc.) every time you save a new waypoint this way. Three-digit numbering of waypoints will restart at S001, which means the 958 will start to overwrite the existing numbered waypoints, as soon as the 958 reaches the maximum number of saved waypoints you’ve set.

For details about using the MAX SAVED WAYPT # function in the DISPLAY OPTIONS menu, see ”Choosing the number of saved waypoints” starting on page 166.

Using the MOB key

To enter Man Overboard mode (MOB), press the MOB key to display the MAN OVERBOARD info window. The 958 will save your position and display it on the CHART screen as a waypoint with the name – MOB– and the dot waypoint symbol.

The zoom level will be set automatically to the maximum detail of 1/4 nm range. The CHART screen locks, showing your vessel’s position and the MOB location. The MOB location has


Chapter 3 - Using the Controls immediately become your current waypoint, with new distance and bearing information displayed on the right side of the screen.

CAUTION!

INVOKING MOB WHILE USING AN AUTOPILOT

Some autopilots try to steer your vessel according to any bearing changes output by the 958, regardless of the severity of the change. Others automatically disengage when a severe or abrupt turn is required. For details about this procedure, check your autopilot manual.

To leave MOB mode and return to normal navigation, press the MOB key until the 958 displays the BACK TO NORMAL —

MOB TURNED OFF message. Notice that the waypoint named

-MOB is still stored.

Using the alphanumeric KEYPAD

The 12-key alphanumeric KEYPAD is used to enter numbers, letters, or special characters for waypoint coordinates, names, and similar functions.

Entering numbers

When the 958 expects you to enter only numbers, such as waypoint coordinates, you can use the KEYPAD to enter one digit (0 through 9) with each keypress. The flashing cursor moves automatically to the next digit position.

For entries such as latitude and longitude—where you must enter digits into specific character positions—the cursor starts on the left side of the data area, and you enter characters left to right into their correct positions.

For other numeric entries such as distances—where you can enter numbers of different lengths—you enter the digits


Chapter 3 - Using the Controls calculator-style from the right side of the data area. If you make a mistake, press the CLEAR key to clear the entire number and re-enter it, or press the CURSOR PAD left to re-enter particular digits one at a time.

Entering letters and characters

When the 958 expects you to enter letters, such as waypoint names and descriptions, the operation is slightly different than entering numbers. Each key is labeled with three letters and a digit. For example, the upper left key is labeled with the letters

A , B , C and the digit 1 . Press this key once to display the letter

A . Press this key again to display the second letter, B . Pressing a third and fourth time displays the letter C and the digit 1 , respectively. A fifth press brings you back to the letter A again.

To enter a character, first find the key containing the character, and press that key one to four times to display the desired character. To move the cursor to the next character position, press the CURSOR PAD right.

Using the CLEAR and ENTER keys

The KEYPAD has CLEAR and ENTER keys for erasing or entering data that’s already been typed. The CLEAR key removes any data you’ve already typed—resetting the field to all blanks or restoring the original value. The ENTER key is always the last step when entering or changing data, or when acknowledging an action.

The CLEAR and ENTER keys are also used to reject or accept actions displayed in question boxes that appear on the screen.

For example, if you press the GO TO CURSOR key, the 958 displays the message START NAVIGATING TO CURSOR

POSITION? YES... PRESS “ENTER” NO... PRESS “CLEAR ,” and waits for you to press the ENTER or CLEAR key.

Using the menu keys

The six round MENU keys on the right side of the screen have a variety of functions that usually depend on the screen you’re currently displaying.



Using the BRIGHTNESS key

To get the best picture for the current conditions, the 958’s screen may require minor adjusting for different viewing angles, temperature conditions, etc. Press the BRIGHTNESS key (the unlabelled double arrow) to adjust the screen’s brightness.

Using the IN and OUT keys

On the CHART and the 3D STEER screens and on the radar, each press of the IN key zooms in to double the scale, and each press of the OUT key zooms out to halve the scale.

On other screens, you can also use the IN key and OUT keys to adjust the transparency of the video image, if already displayed: Pressing IN lets you see more of the video image, and pressing OUT lets you see more of the screen underneath the image.



4

Using the Chart Screen

Understanding electronic charts . . . . . . . . . . . . 38

Understanding nav aids . . . . . . . . . . . . . . . . . . . . 39

Zooming in and out . . . . . . . . . . . . . . . . . . . . . . . . . 41

Controlling the cursor on the chart screen . . 42

Comparing vessel and browse modes . . . . . . . 44

Splitting the screen . . . . . . . . . . . . . . . . . . . . . . . . . 46

Controlling the screen . . . . . . . . . . . . . . . . . . . . . . 48

Rotating the chart . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Setting up the chart screen . . . . . . . . . . . . . . . . . 53

Using distance and bearing mode . . . . . . . . . . . 57

T his chapter explains the electronic chart, the different chart modes (vessel and browse), the various chart symbols and their meanings, and how to set up the chart display.

Page 37

Chapter 4 - Using the Chart Screen

Understanding electronic charts

Each Navionics chart cartridge contains electronic chart data from several paper charts. Electronic charts have much of the information from the original paper charts, although spot depth soundings, some nav aids, and other data may be missing. When used with caution, electronic charts open up a world of navigational accuracy and simplicity.

CAUTION!

Don’t become overly confident when using electronic charts.

Always be cautious!

Chart boundary lines

The 958 displays the boundary line of each chart on the

CHART screen. To turn this feature off, press the CHART

SETUP key on the CHART screen, then press the CHART

DETAIL key and turn off the CHART EDGES option.

Chart details

If you move from a highly detailed chart to a less detailed one, you may see a sudden change in the detail shown on the screen, just as if you had changed from one detailed paper chart to a less detailed one. You may be able to use the displayed boundary lines to predict when this change in detail is going to happen.



Understanding nav aids

The nav aids on the CHART screen represent a variety of standard “aids to navigation” used on coastal and inland waterways throughout the United States. Nav aids are displayed on the CHART screen as colored circles with white letters. Most of these aids comprise buoys, lights, lighthouses, and daybeacons, which typically are maintained by the U.S.

Coast Guard. Nav aids warn you of hidden dangers, such as underwater hazards, and to help you to safely navigate specific waterways and channels.

CAUTION!

Nav aids have been converted from official paper charts into the electronic format on your screen, and therefore aren’t necessarily as accurate as the paper charts. You can expect about a 95 percent accuracy rate. In some areas, only the most important nav aids may be shown.

Buoys

Buoys are the most common type of nav aid. The 958 shows green and red channel markers as green and red circles, respectively.

Approach buoys are shown as circles with black on the upper half and white on the lower half.

Sound buoys (featuring an audible signal, such as a bell, gong, or whistle) are identified by a description in the INFO BAR such as BELL , WHIS , GONG , or HORN) .

Some nav aids have no chart symbol, and are shown on the

CHART screen as text only.

When you move the cursor onto a nav aid, the 958 displays a description in the INFO BAR at the bottom of the screen, along with the distance and bearing from your vessel to the nav aid.



Landmarks

There are other objects shown on the CHART screen that aren’t classified as nav aids, including various onshore landmarks.



Zooming in and out

To get a closer look at the chart area around your vessel or around the cursor, press the IN key to zoom in. To see a wider area, press the OUT key to zoom out. Each press of the IN or

OUT key approximately halves or doubles the chart scale, respectively.


At the highest detail for a particular chart, you can use the 958 as a precision plotter. When you zoom in past that level, the center of the chart is magnified to fill the screen and all text and symbols are doubled in size. Zooming in still further causes the 958 to remove all chart detail from the screen for safety reasons, leaving only your vessel, its track, user-entered waypoints, and the lat/lon grid.

Page 41


As a reminder that no charted hazards or nav aids are shown, the 958 displays the words NO CHART multiple times across the screen. Even without any chart data displayed, you can still use the 958 as a precision plotter

NOTE:

If the chart has a radar overlay and if you change the chart’s scale (by zooming in or out), the scale of radar changes to match. If you change the scale of radar, the scale of the chart also changes to match, even if the chart isn’t visible at the time. However, if the radar overlay doesn’t appear on the chart, you can scale the chart and radar separately.

Controlling the cursor on the chart screen

Pressing the CURSOR PAD displays the cursor symbol on the

CHART screen. Further pressing of the CURSOR PAD will move the cursor across the screen. If you have trouble finding the cursor in a busy part of the CHART screen, just look at the sides of the screen for the red cursor pointers: They match up with the cursor.

If you move the cursor right onto an object, such as a displayed waypoint, you will select that object, as indicated by a diamond-shaped box (see left) around the object.

Information about the selected object appears at the bottom of the screen, as shown below.




After pressing the CURSOR PAD to scroll around on the chart, you can press the GO TO CURSOR menu key to start navigating to the designated cursor location. If you place the cursor on a waypoint or nav aid, this menu key would be GO

TO WAYPT or GO TO NAV AID , respectively.

You can use the cursor for the following functions:

•

•

•

• select a nav aid or waypoint, to:

>

>

> show its name, lat/lon, and distance and bearing navigate to it add it to a route designate a point on the chart, to:

> show its lat/lon

> navigate to it

> add it to a route

> store as a waypoint select a leg of a route to follow or edit view a new area of the chart by moving the cursor to the edge of the chart

Page 43


Comparing vessel and browse modes

The 958 offers two display modes:

• vessel

• browse

As long as the CONTROL key shows (CHART) , Pressing the

CURSOR PAD at any time instantly changes the display from vessel mode to browse mode. When you’re in browse mode, pressing the VESSEL menu key at any time instantly displays your vessel in the center of the CHART screen, returning the

958 to vessel mode.

Vessel mode

Vessel mode is indicated by the word VESSEL in the upper right corner of the screen. In this mode, you can perform the following functions:

Page 44

•

•

• see your vessel’s present position in relation to your intended course line and any nearby waypoints, nav aids, land masses, etc.

split the screen ( SPLIT key) to display the chart simultaneously with radar and/or the optional sounder screen and/or a video image; for details, see ”Splitting the screen” starting on page 46 control the chart ( CONTROL key); for details, see

”Controlling the screen” starting on page 48


•

•

•

•

Chapter 4 - Using the Chart Screen rotate the chart ( ROTATE key); for details, see ”Rotating the chart” starting on page 49 restart your course line from your present position to your intended waypoint ( RESTART key); for details, see

”Restarting navigation” starting on page 124 display or change the setup functions for the CHART screen ( CHART SETUP key); for details, see ”Setting up the chart screen” starting on page 53 display position details at the bottom of the screen ( MORE

INFO key)

Browse mode

Browse mode is indicated by the word BROWSE in the upper right corner of the screen. In this mode, you can perform the following functions:


•

•

•

• view any area on the chart by moving the cursor there

( CURSOR PAD ) quickly determine distance and bearing to other points on the CHART screen ( CURSOR PAD ) split the screen ( SPLIT key) to display the chart simultaneously with radar and/or the optional sounder screen and/or a video image; for details, see ”Splitting the screen” starting on page 46 control the chart ( CONTROL key); for details, see

”Controlling the screen” starting on page 48

Page 45


•

•

•

• rotate the chart ( ROTATE key); for details, see ”Rotating the chart” starting on page 49 return to vessel mode ( VESSEL key) display or change the setup functions for the CHART screen ( CHART SETUP key); for details, see ”Setting up the chart screen” starting on page 53 specify points to go to on the CHART screen ( GO TO

CURSOR key)

Splitting the screen

If you have radar and/or the echo sounder installed and operational, you’ll see the SPLIT key when you view the

CHART screen; otherwise, you’ll see a VIDEO key. The following discussion assumes that the SPLIT key is available.

•

•

•

You can split the screen in the following ways:

•

•

•

Overlay video

View the chart alone

View the chart and sounder together

View the chart and radar together

View the chart, radar, and sounder together

View the radar alone

The following figure shows examples of the available screens.




Video

(overlaying chart)

Chart and sounder

Chart and radar

Chart, radar, and sounder

Figure 3: Examples of split screens

To split the screen:

1. Press the SPLIT key to view the SELECT A SPLIT SCREEN menu:

Page 47


2. Press the key for the split you want.

NOTE:

There’s less room on a split screen than on a full screen. For detailed viewing of the chart, sounder, or radar, choose a full screen.

You can overlay video on any screen listed on the SELECT A

SPLIT SCREEN menu by pressing the VIDEO key. For details on the video overlay, see ”Using the video display option” starting on page 160.

For details on the sounder, see the Northstar 490 Operator’s

Manual (part number GM490).

For details on radar (and the radar overlay), see

”Understanding Radar Functions” starting on page 125.

Controlling the screen

f you have radar installed and operational, you’ll see the

CONTROL key when you view the CHART screen; otherwise, you won’t see any key. The following discussion assumes that the CONTROL key is available.

You are controlling the chart when the word CHART appears on the CONTROL key.

The CONTROL key (like the ROTATE key, and several other keys in the 958) has two parts: the upper part shows the


Chapter 4 - Using the Chart Screen function of the key; the lower part (in blue) shows the current status of the function:

Function (for example, control)

Status (for example, chart)

You press the CONTROL key once to select the key’s function

(a small arrow appears next to the function). You then press the key again to select the key’s status (a small arrow appears next to the status). To choose CHART or RADAR , press the key repeatedly until it shows the status you want:

You control only one function—chart or radar—at a time.

Rotating the chart

The chart rotation feature lets you change the angle of the charts that are displayed on the CHART screen. As long as you’re in vessel mode, you can turn charts to any one of the following angles:

•

•

North up - You’ll see north pointing straight upwards (the chart isn’t turned).

Course-up - You’ll see your vessel’s current direction of travel—whatever that direction is—pointing straight upwards. Course-up represents your true COG as determined by the GPS receiver. The 958 ignores any course changes if your speed is under half a knot. The chart will rotate sooner for rapid turns than for slower ones.

NOTE:

Your COG is often different from the heading, so what you see straight ahead in the real world may be different from what’s displayed on the screen.



•

• Heading-up - This angle is available only if you have radar installed and enabled. Heading-up shows the radar heading, which may not be identical to the course-over-ground. When you select heading-up, the heading line on the radar image points straight upwards.

The heading line allows you to compare the radar view with the view in front of the vessel.

Leg-up - You’ll see your vessel’s current leg to a waypoint—whatever direction that is—pointing straight upwards. The 958 will adjust the chart on a leg-by-leg basis, so the chart turns accordingly whenever you start navigating on a new leg, even if you haven’t turned the vessel yet. Exception: If you select leg-up when you aren’t currently navigating, the 958 automatically uses course-up—until you start navigating along another leg.

If you’re viewing course-up, heading up, or leg-up, the text from the Navionics cartridge is tilted to match the rotation angle in order to avoid text overlap.

You can change the chart rotation right on the CHART screen by pressing the ROTATE key.

The following three screens show how the chart looks if you’re travelling along a sample route that has four waypoints, and you rotate the chart from north-up to course-up and then to leg-up.

Page 50

Figure 1: North-up chart angle (first leg going northwest)



Figure 1 shows the vessel heading northwest on the first leg from the first waypoint to the second one. The chart’s viewing angle is set to north-up. Notice the direction of the north-pointing arrow in the upper right corner.

Figure 2: Course-up chart angle (second leg going east)

Figure 2 shows the same chart, but with the chart’s viewing angle now set to course-up and the vessel on a slightly different course than the second route leg. Notice the new direction of the north-pointing arrow.


Figure 3: Leg-up chart angle (third leg going south)

Page 51


Figure 3 shows the same chart, but with the chart’s viewing angle now set to leg-up and the vessel on a different course than the third leg. Notice the new direction of the north-pointing arrow.

Using chart rotation while browsing

• Course-up or Heading-up (Hdg up) - Suppose that you’re displaying the charts as course-up or heading-up and you press the cursor pad to go into browse mode. If your vessel changes course, you won’t see the chart turn to the new direction until you return to vessel mode by pressing the VESSEL key. You must be in vessel mode to see any changed course angle. This feature lets you keep a steady viewing angle if you’re browsing around on the chart.

• Leg-up - If you’re displaying charts as leg-up and the 958 switches to a new leg, you’ll see the chart rotate to the direction of that new leg even in browse mode—unless you’re actively pressing the CURSOR PAD .

NOTE:

If you’re displaying the charts as either leg-up or course-up, you may see a black line with white space on the other side. This line is the edge of the chart, which is now visible since the chart has been rotated. When the vessel or cursor crosses the line, the display will switch to a new chart.

The edges of other charts in the 958’s built-in world atlas are shown, in addition to those in your local cartridge. These edges are shown as black or red dashed lines.

The lat/lon grid is labelled only when the chart is north-up.


How rotating affects the chart and radar


The rotation of the chart and the rotation of the radar image interact under certain circumstances, as described below.

Assume that the chart and radar are both north-up at the start:

If the CHART screen’s in ...

And the radar image is ...

Overlaid on the chart

Browse mode The chart can’t rotate; but if you change the CONTROL key to RADAR , the chart’s mode automatically switches to vessel (see below)

Not overlaid

The chart can’t rotate but the radar can rotate; so if you change the radar to leg-up, the chart doesn’t change (it stays north-up)

Vessel mode Chart and radar both rotate together, so if you change the radar to leg-up, the chart automatically changes to match (and vice versa)

Chart and radar both rotate but separately; so if you change the radar to leg-up, the chart doesn’t change

(and vice versa)

Setting up the chart screen

To set up the display of data on the CHART screen, press the

CHART SETUP menu key (in either vessel or browse mode)


On the CHART SETUP/STATUS SCREEN you can set up the details on the CHART screen, turn the radar overlay on and off, and adjust the 958’s track control.

Page 53


Choosing the chart details

To set up the chart details, press the CHART DETAIL menu key to display the CHART DETAIL screen.

Page 54

To change any of the options, first press the CURSOR PAD to move the cursor to the desired item, then press the ON/OFF menu key to turn the item on or off (off is represented by two dashes)

Lat/lon grid

The ON setting shows lat/lon lines on the CHART screen. Turn lat/lon lines off when these lines add clutter to your screen, or when you don’t need them.

Text info

The ON setting shows the names of local cities, towns, harbors, channels, bodies of water, etc.

Waypoint names

The ON setting shows the name of each waypoint below its symbol. The OFF setting displays just the symbol itself.



Chart edges

The ON setting shows the outlines of the charts that are on the installed Navionics chart cartridge or the built-in maps. Chart edges are shown as boxes with dotted lines.

Depth

The ON setting shows depth contour lines for low, mid, and deep water areas, for any or all of the three depth levels.

Track line

The ON setting shows your vessel’s track points (the course you’ve already traveled). For more track display options, see

“Changing the track control” starting on page 56.

Waypoints

The ON setting shows your waypoints on the CHART screen, and the OFF setting turns them off, with the exception of waypoints on a route.

Nav aids

The ON setting shows nav aids from the Navionics chart cartridge, and the OFF setting hides the nav aids.

Land masses

The ON setting shows the coloring of land masses to contrast between water and land. The OFF setting shows only coastline, without the coloring.

Turning the radar overlay on and off

Press the RADAR OVERLAY menu key to place a radar overlay on the CHART screen ( ON ) or remove it ( OFF ). For details about the radar overlay, see ”Overlaying radar on the chart” starting on page 128.



Changing the track control

The 958 displays your track history as a series of dots indicating the path you’ve recently traveled. You can choose how often to store a position fix as a point in your track history. The 958 stores up to 1,024 position fixes. When it reaches this limit, the 958 starts erasing the oldest points to add your new points to the track line. The more often you mark your track, the faster you fill up the track memory. The maximum track length depends on how often points are stored.

To display the TRACK CONTROL screen, press the TRACK

CONTROL menu key on the CHART SETUP / STATUS screen.

Page 56

You can choose among the following options for point storage, and the corresponding track length:

•

•

•

•

•

•

•

• every 1 second every 2 seconds every 4 seconds every 8 seconds every 20 seconds every 40 seconds every 1 minute every 2 minutes for 60 minutes total for 120 minutes total for 4 hours total for 8 hours total for 20 hours total for 40 hours total for 60 hours total for 120 hours total

- or -



• FREEZE TRACK (FREEZE TRACK stops the storage of any more points, keeping the track unchanged)

Set the TRACK DISPLAY option to OFF to remove the track display from the CHART screen, while the 958 continues to record the track in its memory. To resume viewing your track, change this option to ON .

To change any one of these options, use the CURSOR PAD to move the arrow to the field you want to change, then press the

EDIT menu key. This causes the field to flash, indicating you should press the CURSOR PAD to select the option you want.

Press the ENTER key when you’re done, or CLEAR to restore the field to its original value.

To clear the track history displayed on the CHART screen, press the ERASE TRACK menu key and the ENTER key.

Press the RETURN menu key twice to return to the CHART screen.

Using distance and bearing mode

The 958 lets you quickly check the distance and bearing between any two points on the CHART screen. You can also use this function to make new waypoints that you define by their distance and bearing from another point.

1. Press the WAYPTS/ROUTES key to display the WAY-

POINTS AND ROUTES screen.

2. Press the DISTANCE/BEARING menu key. The 958 displays your present position at the center of the CHART screen with the cursor directly over it.

3. Press the CURSOR PAD to move the cursor to the first location, and press the SET NEW “X” menu key. A new

“X,” or starting point, is displayed at that location. Distance and bearing information from the “X” point to the cursor’s position is displayed in the INFO BAR . You can move the cursor to various points on the CHART screen and see the distance and bearing from the X point as it moves.



4. To make a waypoint at the next cursor location, press the

ADD WAYPT menu key, then enter its name, symbol, or description on the NEW WAYPOINT screen and press

ENTER to save it.


5

Determining Your Position

Displaying position, COG, and speed . . . . . . . . 60

Using GPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Using DGPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

Using loran . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

Using Phantom Loran . . . . . . . . . . . . . . . . . . . . . . 68

T his chapter explains the 958’s most basic navigational function: determining your position.


Chapter 5 - Determining Your Position

Displaying position, COG, and speed

The 958 uses a high-performance GPS receiver as its primary source of position data, augmented by either the WAAS satellite system, or radiobeacon differential, or both.

Depending on the type of antenna/receiver that’s connected, the 958 can determine and display position coordinates in several different ways:

• as lat/lon coordinates

> from GPS satellites alone

> from GPS plus the radiobeacon differential system

> from GPS plus WAAS satellites

NOTE:

The 958 can display position as Loran TDs if the 958 is connected to a loran receiver. Also, it can display “Phantom Loran” coordinates; that is, if you don’t have a loran receiver, but want to see your position as loran

TDs, the 958 will convert GPS coordinates into Loran coordinates.

Using GPS

Position, COG, and SOG are calculated from the received satellite data, as well as time, date, and an estimate of the 958’s accuracy. To display this position information, press the

CHART key to display the GPS POSITION screen.



You’ll see your lat/lon on the GPS POSITION screen. If GPS data isn’t available, you’ll see dashes instead of numbers.

You can display lat/lon as either degrees, minutes, and seconds, or as degrees, minutes, and thousandths of minutes.

For instructions, see ”Changing your display settings” starting on page 164.

The time of day, and today’s day and date are displayed at the bottom of the screen. You can display time in a 12- or 24-hour format, and you can designate a specific time zone. For instructions, see ”Changing the time zone” starting on page

182.

SOG and COG readings are the result of instantaneous measurements from the satellite signals. GPS speed is updated every second. You can average these readings over a short period of time, however, by changing the GPS speed averaging value (see ”Changing your receiver settings” starting on page

172).

The 958 displays the name of the datum currently in use in the center of the screen. The datum describes the reference of the chart you’re currently using. Most new charts use the

NAD83 or WGS84 datum, which are nearly identical. Make sure the datum that the 958 uses matches the datum shown on the chart cartridge label. Using the wrong datum can significantly reduce accuracy. For more information on selecting the datum for your area, contact your authorized

Northstar dealer.

A brief status summary of the GPS receiver is displayed at the top of the screen. Table 2 describes these various GPS status messages.

Table 2: GPS status messages

Message Meaning

COMM FAIL communication link or the GPS receiver has a problem

3D NAV

2D NAV navigating with 4 or more satellites in 3-D mode navigating with 3 satellites in 2-D mode



Table 2: GPS status messages (continued)

Message Meaning

TRACKING

ACQUIRE one or more satellites are being tracked trying to acquire satellites

SKY SEARCH searching for satellites with no previous information

Viewing GPS satellite status

To display more information about signals received from the

GPS satellites, press the SAT INFO menu key on the GPS

POSITION screen. The GPS SATELLITES screen is displayed showing the received Signal-to-Noise Ratio (SNR) for each satellite (the higher the ratio, the better the quality of the satellite signals), and a satellite map indicating where the satellites are currently located in the sky. Satellites are identified by their PRN number, a two-digit number assigned by the U.S. government. GPS satellites are represented by circles; WAAS satellites are represented by hexagons.

The center of the satellite map represents the center of the sky, and the outer (or last) ring is the horizon. The view is looking down from above, with East to your right and West to your left.

Page 62

The following GPS data is also displayed:


Using DGPS


•

•

ACCURACY: The estimated accuracy--in feet--of the GPS system to be expected at the current time. Your position readings should be more accurate than this estimate 95 percent of the time.

HDOP: This is a technical measure of the quality of your fix. HDOP (Horizontal Dilution of Precision) is calculated from the satellites’ current positions. You’ll usually see an

HDOP value displayed immediately after the 958 is turned on, and before it’s ready to navigate. HDOP can range from an ideal value of slightly less than one, up to poor values of 10 or more. Any value less than two indicates excellent satellite configuration.

When using the 958 with optional radiobeacon DGPS , you’ll usually see position measurements accurate to about one to three meters, speed measurements accurate to about 0.1 knot, and COG measurements accurate to about 0.5 degree. DGPS corrections remove most of the errors caused by atmospheric variations.

NOTE:

When you’re using DGPS as your navigation source, your position coordinates, as calculated by the 958, may actually exceed the accuracy of some charts.



When the DGPS indicator is displayed, it means the 958 is using this higher level of accuracy. When you require this additional accuracy, be sure to check often to see that either the DGPS or WAAS indicators are present.

Displaying DGPS status

To display more information about received DGPS corrections, press the DGPS INFO menu key on the GPS POSITION screen.

The DGPS STATUS screen is displayed, showing the DGPS transmitter currently used.

Page 64

The upper part of the screen shows the beacon’s name, frequency, baud rate, and the beacon’s distance and bearing from your vessel. The lower part of the DGPS STATUS screen shows three bar graphs:

•

•

•

SNR: The Signal-to-Noise Ratio is a good measure of overall signal quality, and should be as high as possible. Values of 15 and higher are best; anything below 10 could indicate poor reception.

SIGNAL: This represents the actual strength of the received signal. This value should be as high as possible, and it varies with distance from the differential transmitter.

NOISE: The NOISE level measures the static caused by lightning and other atmospheric effects, and should be


DGPS message

NO CORRECTIONS

NOT INSTALLED

SC-104 IN OK

SC-104 IN FAIL

RESULTS UNKNOWN

BCN UNHEALTHY

DISABLED

INIT OR SYNCH

Chapter 5 - Determining Your Position low for best results. Table 3 below describes the noise levels.

Table 3: Definitions of noise levels

Noise level value

200 or less

200 - 1,000

1,000 - 3,000

5,000 - 10,000

Meaning excellent good typical at night thunderstorms or electrical noise

A summary of DGPS operations is displayed at the bottom of the DGPS STATUS screen. The table below summarizes these status messages.

Table 4: DGPS status messages

Meaning

Beacon receiver status message is being received, but no SC-104

DGPS corrections are present.

No beacon receiver status message is being received, nor has an external DGPS source been chosen.

An external source has been chosen, and the required data is being received.

An external source has been chosen, but the required data isn’t being received.

The communication link to the GPS receiver has a problem.

The beacon station in use is either unhealthy or unmonitored.

DGPS has been turned off by the user (to enable DGPS, see

”Changing your receiver settings” starting on page 172).

The GPS receiver is trying to initialize the messages from the beacon receiver.



Table 4: DGPS status messages (continued)

DGPS message

TOO FEW CORRECTIONS

POOR BCN DOP

OLD CORRECTIONS

DGPS IN USE/OK

UNKNOWN

Meaning

DGPS is off because not enough satellites with corrections are available.

DGPS is off because the satellites with corrections have poor geometry (DOP is an acronym for Dilution Of Precision).

DGPS is on, but the current corrections are older than the timeout you’ve set in the receiver options (see ”Choosing a DGPS corrections time-out” starting on page 176).

DGPS is on and the corrections are current.

An unknown status code has been received from the GPS receiver.

Using loran

This section explains how you can use the 958 to navigate using displayed loran coordinates if the 958 is connected to an loran receiver (such as the Northstar 800). If you don’t plan to use loran, you can skip this section.

Selecting and displaying loran

To display loran time differences (TDs) from a connected loran receiver:

1. Press the STAR key to display the OPTIONS/SERVICE

INFO screen.

2. Press the NAVIGATION OPTIONS menu key, then select the NAVIGATION SOURCE field.

3. Press the EDIT menu key, then press the CURSOR PAD to display EXTERNAL LRN as the position source.

4. Press the ENTER key, then press the RETURN menu key.

5. Press the CHART key to display the GPS POSITION screen.

6. Press the CHECK LORAN key to display the LORAN POSI-

TION screen.



Press the L/L TDS menu key several times to display either the particular pair of TDs you want to use, or the loran-derived latitude/longitude.

NOTE:

If you want the 958 to display loran position coordinates from a connected loran, the loran must support the standard NMEA 0183 “RMA” output data sentence structure. Without this output capability, the 958 won’t receive position data from the loran.

Checking GPS status

To display GPS coordinates and signal status, press the CHECK

GPS menu key. The 958 continues to navigate using loran, and will display loran data the next time you display the

LORAN POSITION screen.

Viewing loran status

To check the quality of signals being received by your loran, press the LORAN INFO menu key from the LORAN POSITION screen. The SNR for each loran transmitting station is displayed graphically on the LORAN INFO screen.

Setting loran GRI

To change the four-digit loran Group Repetition Interval (GRI), press the SET GRI menu key on the LORAN POSITION screen.

For the 958 to accurately convert the loran’s TDs to latitude/


Chapter 5 - Determining Your Position longitude position fixes, the GRI must correctly match the GRI being used by your loran receiver.

Viewing loran warnings

Three possible loran warning indicators obtained from any

Northstar 800 series loran receiver are displayed to the right of each TD. (These indicators are available only from Northstar

800 series lorans.)

Table 5: Northstar 800 loran warning indicators

Indicator

SNR

BLNK

CYC

LOCK

Meaning

Signal-to-Noise Ratio is low—use caution

Coast Guard is transmitting a blink signal, indicating a probable transmitter problem

The receiver has detected a possible cycle slip

The loran has locked onto the loran track point (this isn’t a warning indicator, but an indication of normal performance)

The L/L indicator to the left of a TD designates it as one of the two TDs that the loran receiver has chosen to use to calculate latitude and longitude.

The F/L indicator to the left of a TD indicates that it has been forced to be used to calculate latitude and longitude.

Returning to GPS navigation

To return to using GPS signals for navigation, repeat the steps shown for selecting loran in “Selecting and displaying loran” on page 66, but specify GPS instead of loran.

Using Phantom Loran

If you have lists of fishing spots and other waypoints that you recorded as loran time differences (TDs), the 958 can automatically convert its GPS coordinates into TDs—in real time, as you travel—letting you display your current position as



TDs. The accuracy from this conversion is generally better than 500 to 1500 feet.

This feature is called Phantom Loran, which helps you move from using loran to using GPS. Phantom Loran lets you display your position as TDs, or enter waypoints as TDs. You can use the 958 to simulate the full operation of a loran receiver, using all of the 958’s navigation functions as if it was actually receiving loran signals.

These calculated TDs won’t exactly match the positions of previously recorded TDs obtained directly from actual loran signals. In most areas, TD errors shouldn’t exceed one microsecond. However, larger errors are possible in areas with poor configuration, or for which the 958 doesn’t have accurate, factory-programmed ASF correction points.

Selecting and displaying Phantom

Loran

To display position coordinates as Phantom Loran TDs:


INFO screen.

2. Press the NAVIGATION OPTIONS menu key, then highlight the NAVIGATION SOURCE option.

3. Press the EDIT menu key, then press the CURSOR PAD to select PHANTOM LRN.

4. Press the ENTER key, then press the RETURN menu key.

5. Press the CHART key to display the GPS POSITION screen.

6. Press the CHECK LORAN key to display the PHANTOM

LORAN screen.



Viewing Phantom

Loran TDs

Press the L/L TDS menu key several times to display either the particular pair of TDs you want to use, or the GPS-derived latitude/longitude.

Setting Phantom

Loran GRI

Press the SET GRI menu key to change the GRI to be used in calculating the displayed TDs. Press the CURSOR PAD to display the available GRIs one at a time. When the GRI is correct, press the ENTER key.

Checking GPS status

Press the SAT INFO menu key to display the status of the GPS receiver.

Checking DGPS status

Press the DGPS INFO menu key to display the current status of the differential receiver, including SNR , SIGNAL, and NOISE values.


6

Understanding the Waypoints Function

Introducing waypoints . . . . . . . . . . . . . . . . . . . . . 72

Displaying waypoints . . . . . . . . . . . . . . . . . . . . . . . 72

Displaying waypoint coordinates . . . . . . . . . . . 74

Creating new waypoints . . . . . . . . . . . . . . . . . . . . 75

Creating avoidance-area waypoints . . . . . . . . 80

Editing waypoints . . . . . . . . . . . . . . . . . . . . . . . . . . 83

Updating waypoint coordinates . . . . . . . . . . . . 84

Moving waypoints/routes between units . . . 85

Transferring waypoints to and from a PC . . . 91

T his chapter explains all of the functions associated with creating, displaying, editing, and managing your waypoints.


Chapter 6 - Understanding the Waypoints Function

Introducing waypoints

The term waypoint refers to a point (a location) that you’ve entered into the 958’s memory. The waypoint appears on the chart with the symbol you’ve chosen. In contrast, the term nav aid refers to a point that’s permanently stored on the

Navionics chart cartridge.

Here are some of the functions you can perform with waypoints:

• go to a point on the CHART screen in one step (making a

“quick” waypoint)

• store waypoints into the 958

• go to these waypoints

• string these waypoints together to form routes

• follow these routes

• edit or erase waypoints or routes

• plot waypoints or routes

•

• transfer all waypoints (and routes) between any two 958’s transfer waypoints (and routes) from the 958 to a PC, and back again

Displaying waypoints

You can display waypoints in any of four ways:

•

• A graphic (chart) view of waypoints

A list of up to 30 local waypoints, sorted by nearest first

•

• A list of all waypoints, sorted alphabetically

A list of up to 30 local avoidance waypoints, sorted by nearest first

First, press the WAYPTS/ROUTES key, then the WAYPOINTS menu key. To view the LOCAL, ALPHA, and AVOID waypoint lists, press the NEXT VIEW menu key. The 958 displays the type of list at the top of the screen. Each press of the NEXT

VIEW menu key cycles through the waypoint viewing list in


Chapter 6 - Understanding the Waypoints Function the order shown above. Press the CURSOR PAD to move up or down the list. (If your 958 is new, these lists will be empty.)

WAYPOINTS CHART screen: Waypoints are displayed on the chart

WAYPOINTS (LOCAL) screen: Up to 30 waypoints within 100 nm, nearest one first

ROCKS

PILING

WRECK

AVOID1

WAYPOINTS (ALPHA) screen: All waypoints in alphabetical order

WAYPOINTS (AVOIDANCE) screen : Up to 30 avoidance waypoints within 100 nm, nearest one first



On the chart screen

The WAYPOINTS CHART screen displays all the waypoints in the area around the cursor, as you move the cursor around the chart. If necessary, press the IN and OUT keys to see the waypoints.

Note: If you’ve turned off the display of waypoints on the

CHART screen, you’ll only see waypoints that are currently in use for navigation.

On the local screen

The WAYPOINTS (LOCAL) screen displays up to 30 of the closest waypoints (within 100 nm) in order of distance from your present position. This list is particularly useful when you only want to deal with the waypoints in your area. Even though you may have hundreds of stored waypoints, often the local waypoints are the only ones you may be interested in at the moment.

On the alpha screen

The WAYPOINTS (ALPHA) screen displays all stored waypoints in alphabetical order. Waypoints with a digit as the first character appear near the beginning of the list. Those starting with a dash or parenthesis are at the end.

On the avoidance screen

The WAYPOINTS (AVOIDANCE) screen displays up to 30 of the closest avoidance waypoints (within 100 nm) in order of distance from your present position.

Displaying waypoint coordinates

When you display a waypoint list, you can see their coordinates in any of the following ways by pressing the

COORD OPTION menu key:

•

•

• as lat/lon coordinates as distance and bearing from your position (often the most useful way to display coordinates, since it may be easier to understand “3 miles north” than lat/lon digits) as loran time differences



The small letter “S” to the right of the waypoint name tells you that the displayed coordinates, either lat/lon or TDs, were the ones used to originally store the waypoint.

Creating new waypoints

There are two easy ways to create new waypoints:

•

• graphically--by storing their positions after pointing to them on the CHART screen numerically--by entering position coordinates as lat/lon, loran TDs, or distance and bearing on the NEW WAYPOINT screen

Assigning a name and description

To permanently store a waypoint, you must give it a name .

The name can be from one to six characters long, and must be different from all the other waypoint names stored in the 958.

You can also enter a description of up to 16 characters on the line below the name.

Assigning a symbol

You can give the waypoint a symbol so you can easily identify it on the CHART screen. When creating or editing waypoints, you can choose from any one of 16 symbols, eight of which are shown below.

ANCHOR FISH FLAG X


FUEL WRECK DANGER DOT

Figure 4: Waypoint symbols

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Entering waypoints graphically (on the chart screen)

To enter waypoints on the CHART screen:

1. Press the WAYPTS/ROUTES key.

2. Press the WAYPOINTS menu key. You may have to press the NEXT VIEW menu key to display the graphical

WAYPOINTS screen.

3. Press the CURSOR PAD to move the cursor where you want to add the new waypoint. You can zoom in or out, as necessary, to precisely place your waypoint.

4. Press the ADD WAYPT menu key to display the NEW

WAYPOINT screen.




5. Enter a name for the waypoint and, if you want, a description, as previously described.

6. Choose a symbol for the waypoint by pressing the

SYMBOL menu key to find a symbol you want (see

”Assigning a symbol” starting on page 75).

7. Adjust the coordinates, if desired.

The position coordinates displayed in the lat/lon box are the ones designated by the cursor location on the screen.

You can adjust them here, if necessary, after pressing the

CURSOR PAD to move the cursor down into the LAT and

LON fields.

If you want to switch among displaying coordinates as lat/lon, as loran TDs, or as distance and bearing, press the

COORD TYPE menu key:

>

>

>

For loran TDs, you can enter any legitimate pair of TDs and the GRI for the pair. After entering the GRI, check the name of the GRI that’s automatically displayed to ensure it’s correct.

For distance and bearing from your present position, leave the FROM point set to -HERE-, and enter the bearing and the distance to the desired waypoint.

For distance and bearing from any other stored waypoint, press the FROM menu key to display a list of waypoints. Press the CURSOR PAD to select the desired waypoint and press the ENTER key. Enter the bearing and the distance from the designated waypoint to the new waypoint. If you change your mind and want to return to specifying distance and bearing from your present position instead of from another waypoint , press the FROM HERE menu key on the waypoint list screen.

NOTE:

If you’ve travelled to a part of the world that’s south of the Equator or east of the Prime Meridian (running through Greenwich, England), the 958 automatically displays your lat/lon coordinates as S or E , respectively, instead of N and W . The N-S-E-W key lets you manually change these hemispheric values if necessary. When the cursor is flashing anywhere in the LAT or LON fields, press the N-S-E-W key to change the hemispheric values.

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8. Press the ENTER key to store the new waypoint and return to the graphical WAYPOINTS screen.

Entering waypoints numerically (on the list screen)

To enter waypoints numerically:

1. Press the WAYPTS/ROUTES key.

2. Press the WAYPOINTS menu key.

The 958 displays a waypoint list if you had displayed a list during a previous viewing; however, if you had previously displayed a graphical screen, you must press the NEXT

VIEW menu key to display the list views. These list views comprise waypoints listed numerically in order of distance ( WAYPOINTS LOCAL list, as shown below), alphabetically ( WAYPOINTS ALPHA list), or by avoidance

( WAYPOINTS AVOIDANCE list).



3. Press the ADD key to display the NEW WAYPOINT screen.


4. Enter a waypoint name and optional description.

5. Choose a symbol for the waypoint by pressing the

SYMBOL menu key to find the symbol you want.

6. Enter the waypoint’s coordinates. If you want to switch among displaying coordinates as lat/lon, as loran TDs, or as distance and bearing coordinates, press the COORD

TYPE menu key:

> For loran TDs, enter any legitimate pair of TDs and the

GRI for the pair. After entering the GRI, check the name of the GRI that’s automatically displayed to ensure it’s correct.

> For distance and bearing from your present position, leave the FROM point set to -HERE-, and enter the bearing and the distance to the desired waypoint.

> For distance and bearing from any other stored waypoint, press the FROM menu key to display a list of waypoints. Press the CURSOR PAD to select the desired waypoint and press the ENTER key. Enter the bearing and the distance from the designated waypoint to the new waypoint. If you change your mind and want to return to specifying distance and bearing from your present position instead of from another waypoint , press the FROM HERE menu key on the waypoint list screen

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7. Press the ENTER key to permanently store the new waypoint, which you can edit or delete at any time.

Don’t enter a number into the

NOTE:

WARN RADIUS box unless you want to make this waypoint an avoidance point, as described below.

Creating avoidance-area waypoints

You can make avoidance areas from new or existing waypoints. If you travel into an avoidance area, the 958 will sound a beeping alarm and flash the star symbol on the screen.

The 958 displays an avoidance area on the CHART screen as a waypoint surrounded by a circle. The circle is the avoidance area’s warning radius, which you set when you create or edit the waypoint. The 958 gives you the option to use the international “slashed circle” no-entry symbol as the avoidance point’s symbol to help you quickly see it on the chart.




CAUTION!

The avoidance alarm is only as an extra safety feature to help alert you to possible hazards. It doesn’t replace local knowledge, proper use of charts, the person on watch, or any other aspects of good seamanship that are required to safely navigate.

NOTE:

The waypoint is treated as an avoidance point only if you specify a warning radius larger than zero. In other words, just assigning a waypoint with the slashed circle symbol doesn’t mean the 958 will treat that waypoint like an avoidance point. Also, you must turn on the 958’s avoidance area alarm (see “Setting the avoidance-area alarm” on page 82).

To make a new waypoint into an avoidance area:

1. Press the WAYPTS/ROUTES key, then press the

WAYPOINTS key.

2. Press the ADD menu key to display the NEW WAYPT screen.

3. Enter a distance in the WARN RADIUS box at the bottom of the screen. The warning radius can be as large as 4.9

nautical miles. Be sure to allow a little extra distance around the hazard area so you’ll have time to respond, by turning or stopping after you hear the alarm, and to allow for the typical accuracy of the navigation source in use.

To make an existing waypoint into an avoidance area:

1. Press the WAYPTS/ROUTES key, then press the

WAYPOINTS key. If necessary, press the NEXT VIEW menu key to display the waypoint list screen.

2. Use the CURSOR PAD to select the desired waypoint, then press the EDIT menu key.

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3. Move the cursor to the WARN RADIUS box at the bottom of the screen, and enter the warning radius—up to 4.9 nm.

4. Press the ENTER key.

Setting the avoidance-area alarm

If you’ve made a waypoint into an avoidance area, the 958 will sound an alarm when you enter that area, but only if you’ve turned on the alarm.

To set the audible avoidance-area alarm:

1. Press the STAR key to display the ALARMS screen.

2. Press the CURSOR PAD to select the ALARM AUDIO option.

3. Press the EDIT ALARM menu key.

4. Press the CURSOR PAD to change the setting to ON .

5. Press the ENTER key to make your selection, or CLEAR to leave it unchanged.

NOTE:

If you want to set the 958’s alarm to sound only when you enter an avoidance area, turn off the anchor drag, cross track, arrive radius, and DGPS alarms. The alarm will now beep only when you enter an avoidance area,

(or when you lose GPS or loran navigation signals, but for no other reason).



Editing waypoints

You can change any information about an existing waypoint

(except for the type of coordinates used to save it) or erase it entirely by using the 958’s waypoint editing function.

Changing waypoints

To change a waypoint’s name, description, position coordinates, or warning radius:

1. Press the WAYPTS/ROUTES key, then the WAYPOINTS menu key. The 958 displays waypoints in whatever format you last used: WAYPOINTS CHART screen, WAYPOINTS

( LOCAL) screen, WAYPOINTS (ALPHA) screen, or

WAYPOINTS (AVOIDANCE) screen. If necessary, press the

NEXT VIEW menu key to display the format you want.

2. To select a waypoint on the list screens, press the

CURSOR PAD . To select a waypoint on the WAYPOINTS

CHART screen, move the cursor onto the waypoint to highlight it.


3. To edit a waypoint on a list screen, press the EDIT menu key. To edit a waypoint on the WAYPOINTS CHART screen, press the EDIT WAYPT menu key.

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The EDIT WAYPOINT screen appears, allowing you to make changes just as if you were entering a new waypoint. Press

ENTER when done.

If there’s a warning radius entered, set it to zero if you want to remove the avoidance feature from this waypoint.

Note: If you move the waypoint, any routes containing this waypoint will be changed.

Erasing waypoints

To permanently erase the waypoint, press the ERASE menu key on the EDIT WAYPT screen, then press the ENTER key.

NOTE:

You can’t erase a waypoint if it’s used in a route—you must first remove it from the route. For details about editing routes, see ”Editing a route” starting on page 100.

Updating waypoint coordinates

Before electronic chart navigators, a waypoint’s position was usually taken from a paper chart by measuring the approximate coordinates with whatever accuracy the chart allowed. When you travelled to that waypoint, however, its position might have been slightly different than what you expected.



With the 958’s coordinates’ update feature, when you get to the actual spot location of the waypoint, you can update the waypoint by setting its coordinates to your present position.

You can do this on the WAYPOINTS CHART screen or any of the waypoint list screens.

You can also use this same feature to convert approximate loran TD coordinates to precise GPS coordinates.

Updating from the chart screen

To update the waypoint’s coordinates to your exact position at the moment you press the UPDATE COORD menu key:

1. Select the desired waypoint on the CHART screen (its name and coordinates are displayed in the INFO BAR ).

2. Press the WAYPTS/ROUTES key, then WAYPOINTS menu key. If necessary, press the NEXT VIEW key to display the

WAYPOINTS CHART screen, then press the EDIT WAYPT menu key.

3. When ready, press the UPDATE COORD menu key.

4. Press the ENTER key (or press CLEAR to cancel).

Updating from a list screen

1. Press the WAYPTS/ROUTES key, then the WAYPOINTS menu key.

2. If necessary, press the NEXT VIEW menu key to show the

LOCAL screen. Press the CURSOR PAD to select the desired waypoint.

3. Press the EDIT menu key.

4. Press the UPDATE COORD menu key.

5. Press the ENTER key (or press CLEAR to cancel).

Moving waypoints/routes between units

The 958’s import/export function lets you transfer all waypoints and routes between two 958’s (or Northstar 941,

951, or 952).

NOTE:

To import or export waypoints and routes to and from older Northstar units, these older units must have software version 3.12 or higher


Chapter 6 - Understanding the Waypoints Function installed. To obtain any necessary upgrades, please see your authorized

Northstar dealer.

You can import and export waypoints and routes between the following Northstar units:

•

• two 958’s a 958 and a 952, or 951, or 941

Only one unit, called the “master,” actually enters the import/export function. The other unit can remain in normal operation, including the displaying of different screens, as long as you do not add or change any of its waypoints or routes during the actual transfer process.

You can designate either of the units to be the master since both units have the ability to import and export waypoints and routes. However, once you do select the master unit, just be sure to choose the right function for what you want to do: import waypoints and routes from the second unit , or export waypoints and routes to the second unit ).

Connecting the two units

The two units must be properly connected with the correct cabling, interface ports, and port setting. For interfacing information, contact your authorized Northstar dealer.

Moving waypoints and routes into a unit

Page 86

When you move waypoints and routes into unit 1 (the designated master) from unit 2, the entire contents of unit 2 are imported into unit 1. Also, if any exact waypoint or route name matches exist, the waypoints or routes from unit 2 will overwrite the waypoints or routes already in unit 1.

NOTE:

If you press any function key on the master unit during the transfer, the error message TRANSFER ABORTED BY KEY HIT will be displayed, the process will be aborted, and the master unit will display the particular screen accessed by that function keypress. You can press any key on the other unit, however, without interrupting the transfer process.

To purposely stop the transfer at any time, press the STOP key. If you press the STOP key, the master unit displays the dialog-box message

TRANSFER ABORTED BY KEY HIT , and the status bar displays the message TRANSFER ABORTED . Waypoints and routes transferred up


Chapter 6 - Understanding the Waypoints Function to that point are in the receiving unit (be aware that a particular route may not comprise all of its waypoints due to the transfer interruption). Press the START key again to re-start the entire transfer process (this means that all waypoints and routes, not just the ones already in the receiving unit and the ones left to be transferred, are re-transferred).

1. Choose the unit you’d like to use as the master.

Remember: You can use either of the two units because both units are capable of importing or exporting waypoints and routes. Make sure the second unit is on.

2. At the master unit, press the WAYPTS/ROUTES key to display the WAYPOINTS AND ROUTES screen.


3. Press the IMPORT/EXPORT menu key to display the

IMPORT/EXPORT screen.

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•

•

4. Press the IMPORT menu key to display the IMPORT DATA screen. The status bar in the center of the screen displays the message READY TO TRANSFER to show that the transfer is ready to start.

5. Before transferring, you can check the communication link between the two units by pressing the TEST COMM key. The status bar should display the message REMOTE

LINK OK .

6. To move waypoints and routes into this master unit from the other unit, press the START key. The status bar displays the message TRANSFERRING and updates every second with the number of waypoints and routes already received against the total quantity to be received. The progress bar, located below the status bar, graphically displays the percentage completed.

If there’s a problem with the transfer process, the following messages may appear:

If the other unit is off-line, the master unit displays the dialog-box message COULDN’T GET REMOTE

WAYPT/ROUTE COUNT and the status-bar message

COMMUNICATION ERROR .

If the other unit doesn’t have any waypoints and routes, the master unit displays the dialog-box message NO



•

WAYPTS OR ROUTES TO TRANSFER and the status-bar message NO TRANSFER DONE .

If the master unit is completely full of waypoints and routes with no more room available, the master unit displays the dialog-box message LOCAL UNIT STATUS

ERROR [002] DATABASE FULL and the status-bar message


7. If the transfer is successful, the master unit’s status bar displays the message TRANSFER COMPLETE . You can now press any key to resume other operations.

Moving waypoints and routes from a unit

When you move waypoints from unit 1 (the designated master) into unit 2, the entire contents of unit 1 are exported into unit 2. Also, if any waypoint or route name matches exist, the waypoints or routes from unit 1 will overwrite the waypoints or routes already in unit 2.

NOTE:

If you press any function key on the master unit during the transfer, the error message TRANSFER ABORTED BY KEY HIT will be displayed, the process will be aborted, and the master unit will display the particular screen accessed by that function keypress. You can press any key on the other unit without interrupting the transfer process.

To purposely stop the transfer at any time, press the STOP key. If you press the STOP key, the master unit displays the dialog-box message

TRANSFER ABORTED BY KEY HIT , and the status bar displays the message TRANSFER ABORTED . Waypoints and routes transferred up to that point are in the receiving unit (be aware that a particular route may not comprise all of its waypoints due to the transfer interruption). Press the START key again to re-start the entire transfer process (this means that all waypoints and routes, not just the ones already in the receiving unit and the ones left to be transferred, are re-transferred).

1. Choose the unit you’d like to use as the “master.”

Remember: You can use either of two units because both units are capable of importing or exporting waypoints and routes. Make sure the second unit is on.

2. At the “master” unit, press the WAYPTS/ROUTES key to display the WAYPOINTS AND ROUTES screen.



3. Press the IMPORT/EXPORT menu key to display the

IMPORT/EXPORT screen.

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4. Press the EXPORT menu key to display the EXPORT

DATA screen. The status bar in the center of the screen displays the message READY TO TRANSFER to show that the transfer is ready to start.

5. Before transferring, check the communication link between the two units by pressing the TEST COMM key. If the status bar now displays the message REMOTE LINK

OK , you may begin to transfer waypoints.



6. To move waypoints and routes from this unit into the other unit, press the START key. The status bar displays the message TRANSFERRING and updates every second with the number of waypoints and routes sent compared to the total quantity to be sent. The progress bar, located below the status bar, graphically shows the percentage completed.

If there’s a problem with the transfer process, the following messages may appear:

•

•

If the other unit is off-line, the master unit displays the dialog-box message TRANSFER ABORTED BY

COMMUNICATION TIMEOUT and the status-bar message


If the master unit doesn’t have any waypoints and routes, the master unit displays the dialog-box message NO

WAYPTS OR ROUTES TO TRANSFER and the status-bar message NO TRANSFER DONE .

• If the other unit is completely full of waypoints and routes

(no more room available), the master unit displays the dialog-box message REMOTE UNIT STATUS ERROR [002]

DATABASE FULL and the status-bar message TRANSFER

ERROR .

7. If the transfer is successful, the status bar displays the message TRANSFER COMPLETE . You can now press any key to resume other operations.

Transferring waypoints to and from a PC

If you’ve stored many waypoints or routes in the 958, or if these waypoints are the only record you have of these important locations, you may want to keep a separate copy on your PC.

You can transfer waypoints and routes to your PC by using

Northstar’s loader cable (part number 1100-LC) and special transfer software provided by third-party vendors. This lets you copy, edit, or plot waypoints and routes, and, most important, reload them from your PC into your 958 if they’re accidentally erased or lost due to equipment failure. For


Chapter 6 - Understanding the Waypoints Function transfer software and instructions, and cable ordering information, contact your authorized Northstar dealer.


7

Understanding the Routes Function

Introducing routes . . . . . . . . . . . . . . . . . . . . . . . . . . 94

Creating routes from the chart . . . . . . . . . . . . . . 95

Creating routes from a waypoints list . . . . . . . 97

Saving a route as you travel . . . . . . . . . . . . . . . . 97

Editing a route . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100

T his chapter explains how to create a route from existing waypoints or new waypoints, and how to create a route by saving it as you travel. You’ll also learn how to change the route by inserting, removing, or changing the order of its waypoints.


Chapter 7 - Understanding the Routes Function

Introducing routes

A route is a series of two or more waypoints that form a connected path. You can create routes as you travel, or by placing new or existing waypoints into whatever order you want. Routes can be used to perform the following functions:

•

•

•

• to guide you through a channel or harbor as a quick and efficient path to good fishing spots as the best way around a permanent obstacle, such as an island as guidance on a single long voyage with various “legs” to food and fuel stops along the way, or to other temporary destinations

The straight line between any two waypoints in a route is called a leg . The 958 can follow route legs in a forward or backward direction. You can start following a route in either of two ways:

•

• go directly to any waypoint in the route (cross-track distance starts at zero, because you’re on the course line from your present position to the waypoint) along any leg of the route (cross-track distance starts at your distance from the leg)

Route and waypoint capacity

A route can have up to 35 waypoints. Each route takes up space that otherwise could be occupied by one or two waypoints, plus space for any new waypoints you create in the route. You can store as many as 500 routes in the 958, but the maximum number depends on how the number of stored waypoints. For example, if you’ve stored 700 waypoints, there would be room for about 200 routes.

You can create a route in three different ways:

• creating a route from waypoints and points on the CHART screen

• creating a route from a list of existing waypoints

• saving a route as you travel



Creating routes from the chart

To create a route graphically from the CHART screen:

1. Press the WAYPTS/ROUTES key, and then press the

ROUTES menu key. The names of any previously stored routes are shown on the ROUTES screen.

2. Press the NEW menu key to display the NEW ROUTE screen.



3. Enter the name of the new route using the KEYPAD and

CURSOR PAD . (If you have questions about using these controls, see ”Using the Controls” starting on page 29.)

4. Press the ENTER key. The NEW ROUTE chart screen is displayed where you start selecting waypoints for the new route.

5. To add waypoints to the route, move the cursor to the first waypoint’s location, which can be a nav aid, an existing waypoint, or any unmarked point on the chart. If the cursor has selected an existing waypoint, the menu key will read ADD WAYPT ; if the cursor is on anything else, the menu key will read ADD NEW WP . Press the particular key to add a new waypoint.

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Waypoints that are newly created as you travel are named

(0001), (0002), etc., as you enter them. The parentheses indicate that the waypoint is part of a saved route, and the four-digit number uniquely identifies each waypoint.

Each new waypoint is automatically given a description with the time and date you stored the waypoint.

6. Continue creating the route by moving the cursor to each desired waypoint location and pressing either the ADD

WAYPT or the ADD NEW WP menu key for each new waypoint in the route. A line will be drawn on the NEW

ROUTE screen connecting the waypoints, with small arrows indicating the direction of the route.



7. When you’re done, to go back to the NEW ROUTE screen to see all of the route’s waypoints, press the RETURN menu key, or to display the CHART screen, press the

CHART key .

Creating routes from a waypoints list

To create a route from a list of existing waypoints:

1. Press the WAYPTS/ROUTES key, then press the ROUTES menu key.

2. At the ROUTES screen, press the NEW menu key to display the NEW ROUTE screen.

3. Enter the name of the route using the KEYPAD and CUR-

SOR PAD .

4. If the USE LIST menu key is displayed, press it to change from chart-based editing to list-based editing.


6. At the NEW ROUTE screen, press the INSERT menu key.

The SELECT WAYPT screen appears, which lists all of your stored waypoints. If you want to switch between the

LOCAL and ALPHA lists, press the NEXT VIEW key.

7. Move the cursor to select the desired waypoint, then press the ENTER key to place the waypoint in your route.

8. Repeat Steps 6 and 7 until your new route is complete. To see the route on the CHART screen at any time, press the

CHART menu key; once there, to return to the NEW

ROUTE screen, press the RETURN menu key.

Saving a route as you travel

Another way to create a route is to travel the length of the desired route, pressing the SAVE key at each waypoint you want to store in the route. The 958's save-route function makes this a very simple process: First, you tell the 958 that you want to save a route as you travel, then you press the

SAVE key as you pass each waypoint, then you tell the 958 to stop saving the route when you reach the end of the route.



To begin saving a route as you travel:

1. Press the WAYPTS/ROUTES key, and then press the

ROUTES menu key to display the ROUTES screen:

2. Press the SAVE menu key to begin saving a route automatically. The SAVE ROUTE screen is displayed, asking you to enter the name of the new route to be saved.

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3. Enter the name of the new route to be saved using the

KEYPAD and CURSOR PAD , then press the ENTER key.

The 958 displays the message SAVING TO: ROUTE NAME at the bottom of the ROUTES screen, confirming that your route is now being saved.




4. As you pass the location of each new waypoint, press the

SAVE key. The vessel’s location will be saved as a waypoint, and the waypoint will automatically be added to the route being saved. The waypoint is stored with a name similar to (0001) . The parentheses indicate that the waypoint is part of a saved route, and the four-digit number uniquely identifies each waypoint. Each waypoint is automatically given a description with the time and date you stored the waypoint.

Note: While you’re automatically saving a route, you can access all of the 958’s navigation functions (except you can’t edit the route you’re presently saving).

If at any time you’re not sure if you’re still saving a route, press the WAYPTS/ROUTES key, then the ROUTES menu key to display the ROUTES screen. If you’re still saving a route, the message SAVING TO: will be at the bottom of the screen.

To stop saving a route as you travel:

1. Press the WAYPTS/ROUTES key, then press the ROUTES menu key.

2. Press the STOP SAVE menu key. At the question window

( STOP SAVING TO ROUTE XXX?) , press the ENTER key to answer yes.

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Editing a route

You can edit an existing route on either the CHART screen or on a waypoints list.

On the CHART screen, you can perform the following functions:

•

•

• change the route name add new or existing waypoints to the beginning, middle, or end of the route remove waypoints from the route

On a routes list, you can perform all the functions above, plus:

• you can erase the entire route

Editing a route on the chart screen

To edit a existing route on the CHART screen:

1. Press the WAYPTS/ROUTES key, then press the ROUTES menu key to display the ROUTES screen.



2. Press the CURSOR PAD to select the route you want to change, then press the EDIT menu key. The name of the route is displayed on the EDIT ROUTE screen.

3. If you want to change the route’s name, do so now.

If the message at the bottom of the screen says PRESS

ENTER TO CONTINUE (USING LIST) , press the USE

CHART menu key to edit using the chart.

4. Press the ENTER key to display the EDIT ROUTE chart screen showing the route you selected.


The direction of the route is indicated by a series of small arrows in each leg, and the cursor is in the middle of the screen. From here you can add waypoints to the beginning, middle, or end of the route, as described below.

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Adding waypoints to the beginning of a route

To add waypoints to the beginning of a route:

1. Press the CURSOR PAD to move the cursor onto the first waypoint in the route.

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2. Press the ADD TO FRONT menu key, then move the cursor to the existing waypoint or other location that you want to add to the beginning of the route. As you move the cursor, the 958 displays the new route leg as a dotted line from that first waypoint to the cursor position.

3. If you’ve selected an existing waypoint, press the ADD

WAYPT menu key. If you’ve selected only a cursor position, press the ADD NEW WP menu key (in this case, this waypoint is stored with a name similar to (0001), with the parentheses indicating the waypoint is part of a saved route and the four-digit number uniquely identifying each waypoint).

4. Repeat these steps for each new waypoint or cursor location you want to add to the beginning of the route.

5. When done, to add waypoints to the middle or end of a route, press the CANCEL ADD menu key. To go to list-based editing, press the RETURN menu key. To go back to the CHART screen, press the CHART key.



Adding waypoints to the middle of a route

To add waypoints to the middle of a route:

1. Move the cursor to select the leg of the route where you want to insert a waypoint.

2. Press the SPLIT LEG key, then move the cursor to the existing waypoint or other location that you want to add to the middle of the route. As you move the cursor, the

958 displays the new connecting route legs as dotted lines to and from the new waypoint.


3. If you’ve selected an existing waypoint, press the INSERT

WAYPT menu key. If you’ve selected only a cursor position, press the INSERT NEW WP menu key (in this case, this waypoint is stored with a name similar to (0001), with

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Chapter 7 - Understanding the Routes Function the parentheses indicating the waypoint is part of a saved route and the four-digit number uniquely identifying each waypoint).

4. Repeat these steps for each new waypoint or cursor location you want to insert in the route.

5. When done, to change to adding waypoints to the beginning or end of a route, press the CANCEL INSERT menu key. To go to list-based editing, press the RETURN menu key. To go back to the CHART screen, press the CHART key.

Adding waypoints to the end of a route

To add waypoints to the end of a route:

1. Move the CURSOR PAD to select the last waypoint in the route.

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2. Press ADD TO END menu key, then move the cursor to the existing waypoint or other location that you want to add to the end of the route. As you move the cursor, the

958 displays the new route leg as a dotted line from that last waypoint to the cursor position.

3. If you’ve selected an existing waypoint, press the ADD

WAYPT menu key. If you’ve selected only a cursor position, press the ADD NEW WP menu key (in this case, this waypoint is stored with a name similar to (0001), with the parentheses indicating the waypoint is part of a saved



Chapter 7 - Understanding the Routes Function route and the four-digit number uniquely identifying each waypoint).

4. Repeat these steps for each new waypoint or cursor location you want to add to the end of the route.

5. When done, to add waypoints to the beginning or middle of a route, press the CANCEL ADD menu key. To go to list-based editing, press the RETURN menu key. To go back to the CHART screen, press the CHART key.

Removing waypoints from a route

To remove waypoints from the route (the waypoint is not removed from the 958):

1. Move the cursor to the waypoint you want to remove, then press the REMOVE WAYPT menu key.

2. You can remove more waypoints by selecting them with the cursor and pressing the REMOVE WAYPT menu key.

Even if you remove all the waypoints from a route, the

958 still stores the empty route. To remove the route entirely, see ”Erasing an entire route” starting on page

108.

3. When done, to go to list-based editing, press the RETURN menu key. To go to the CHART screen, press the CHART key.

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Editing a route using a waypoints list

To edit a route from a routes list:

1. Press the WAYPTS/ROUTES key, then press the ROUTES menu key to display the ROUTES screen.

2. Press the CURSOR PAD to select the route you want to change, then press the EDIT menu key. The name of the route is displayed on the EDIT ROUTE screen.

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3. If you want to change the route’s name, do so now.

If the message at the bottom of the screen says PRESS

ENTER TO CONTINUE (USING CHARTS) , press the USE

LIST menu key to switch to list-based editing.



4. Press the ENTER key to display the second EDIT ROUTE screen.


From here you can add or remove any waypoints from the route.

Adding waypoints to a route

1. Press the CURSOR PAD to move the left-hand pointer to the spot where you want to insert another waypoint in between two existing waypoints. (To add a waypoint to the beginning of the route, be sure to position the pointer above the first waypoint, not right onto it.)

2. Press the INSERT menu key to display the SELECT WAYPT screen that lists all your stored waypoints. To switch between the LOCAL and ALPHA lists, press the NEXT

VIEW key. Note: you can’t add an avoidance point into a route.

3. Move the cursor to select the desired waypoint, then press the ENTER key to add the waypoint to the route.

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Removing waypoints from a route

1. Press the CURSOR PAD to move the left-hand pointer directly onto the waypoint you want to remove.

2. Press the REMOVE menu key.

3. Press the ENTER key (or the CLEAR key to cancel the removal).

Erasing an entire route

To erase a route:

1. On the ROUTES screen, press the CURSOR PAD to select the route you want to erase.

2. Press the ERASE menu key.

3. Press the ENTER key (or the CLEAR key to cancel the action).

Editing a route you’re navigating along

If you change a route you’re navigating along, the 958 stores the changes, but they won’t appear in the copy of the route you’re navigating along. To enable these changes, you must start following the route again (see ”Navigating along routes” starting on page 116).


8

Understanding Waypoint/Route Navigation

Navigating to waypoints . . . . . . . . . . . . . . . . . . . 110

Steering to a waypoint . . . . . . . . . . . . . . . . . . . . 112

Navigating along routes . . . . . . . . . . . . . . . . . . . 116

Restarting the course line . . . . . . . . . . . . . . . . . . 118

T his chapter explains the different ways you can navigate to waypoints and along routes, and describes how to get back on course or follow a new course line to your destination.


Chapter 8 - Understanding Waypoint/Route Navigation

Navigating to waypoints

There are several ways you can navigate to waypoints:

•

•

• choose a cursor location or select an existing waypoint — you can do both of these right on the CHART screen enter position coordinates numerically select a stored waypoint from a list of waypoints

Navigating on the chart screen

You can go to a waypoint by choosing a cursor location on the

CHART screen, or by selecting an existing waypoint on the

CHART screen:

1. On the CHART screen, move the CURSOR PAD to choose a cursor location or an existing waypoint or nav aid.

2. If you chose a cursor location, press the GO TO CURSOR menu key. If you selected a waypoint, press the GO TO

WAYPT menu key.


If you selected an existing waypoint, the 958 begins guiding you directly to it.

If you chose a new cursor location, the 958 stores the location as a new waypoint with the name -QUIK, and begins guiding you directly to it. Repeating this same procedure will create a new QUIK waypoint that overwrites the existing one; therefore, you may want to change any

-QUIK waypoints to regular waypoints by giving them unique names. For details about renaming waypoints, see

”Editing waypoints” starting on page 83.

Navigating by entering position coordinates

You can use the KEYPAD to enter waypoint coordinates, and then go to the waypoint:

1. Press the WAYPTS/ROUTES key, then press the QUICK

WAYPOINT menu key to display the QUICK WAYPOINT screen.




2. To display the coordinates you want to enter (as lat/lon, distance and bearing, or loran TDs), press the COORD

TYPE menu key to cycle through the choices:

• lat/lon for any location worldwide

• distance and bearing from “here” (your present position), or from any waypoint stored in the 958

• loran TDs (make sure the GRI displayed is correct, and change it if necessary)

3. Use the KEYPAD to enter the waypoint’s coordinates.

If you like, you can now give the -QUIK waypoint a unique name after you’ve entered its coordinates, since the next QUIK waypoint you make will overwrite this one: Just move the cursor to the NAME field and change the name from -QUIKto a unique permanent name before continuing.

4. Press the ENTER key twice. The 958 begins guiding you directly to the waypoint.

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Navigating to previously stored waypoints

This lets you select a stored waypoint from a list of waypoints, and then go to the waypoint:

1. Press the WAYPTS/ROUTES key, then press the WAY-

POINTS menu key. You may have to press the NEXT VIEW menu key to display the most convenient list (often the

LOCAL list, since the waypoints you navigate to are usually nearby).

2. Press the CURSOR PAD to select the waypoint you want to navigate to.

3. Press the GO TO menu key, then press the ENTER key.

The 958 begins guiding you directly to the waypoint.

Steering to a waypoint

To display information that helps guide you directly to your destination waypoint, press the STEER key. If you press the

STEER key twice, you’ll display two versions of the steering screen: Use whichever one you like.



Choosing a steering screen

Both screens help guide you precisely along a course line, which might follow a harbor channel or a line between shoals and sandbars. Both screens graphically show your cross-track distance, which is the distance you are from your course line.

Both screens show numeric navigation information at the top.

NOTE:

You can also use the CHART screen to steer by when you want to get to a waypoint and don’t need to stay precisely on the designated course line.

Displaying distance and bearing

Both screens show your distance and bearing to the waypoint, and your Speed-Over-Ground (SOG) and Course-Over-Ground

(COG). Your 958 may show an arrow between the SOG and

COG displays, pointing upwards when the trend of your speed is increasing, and down when it’s decreasing.

When you’re less than a mile away from a destination waypoint, you can show the distance to the waypoint in feet by setting the 958’s steering distance precision option to HIGH.

For details, see ”Changing the steering precision” starting on page 171.



Understanding the cross-track display

On the steering screen

The STEERING screen uses a traditional display that shows cross-track distance as how far your vessel symbol is from the center line of the display (your course line). When your vessel symbol points towards the course line, you’re moving closer to the line; when it’s parallel to the course line, you’re keeping a constant distance from the line; and when it points away from the course line, you’re moving further from the line.

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The two short vertical lines near the sides of the screen show the limits of your cross-track distance. This same distance is also displayed in numbers near these vertical lines. If you go over this cross-track distance limit, the 958 issues an alarm and your vessel symbol will flash. To display this alarm message, press the STAR key. To clear the alarm, press the

CLEAR ALARM menu key. To adjust the cross-track limit, see

”Choosing the cross-track scale” starting on page 171.

Note: The direction your vessel symbol is pointing tells you the direction you’re actually travelling. The direction may not be the same as your heading, if any current or wind is present, or if you’re moving at a very low speed.

NOTE:

If you’re following a route and the 958 sequences to a new leg, your vessel symbol will show your COG relative to the new leg and should be straight ahead once you’ve finished turning the vessel.


1


In the center of the STEERING screen is an information box where you can display the following information:

•

•

• Estimated Time Enroute (ETE) to the waypoint, and Estimated Time and Date of Arrival (ETA)

Speed of Advance (SOA), and graphical heading correction

Waypoint name, description, and position coordinates

Press the MORE INFO key to cycle through the three choices.

2


3

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On the 3D steer screen

The 3D STEER screen is similar to the STEERING screen, but displays a three-dimensional view of your vessel with the current waypoint, the course line to the waypoint, and the locations of any other nearby waypoints between your vessel and the destination waypoint. This screen provides a comprehensive view of your progress towards your destination waypoint, graphically showing your position in relation to the course line and nearby waypoints so that you can steer with the utmost precision.

Navigating along routes

To follow a previously stored route, press the WAYPTS/

ROUTES key, then press the ROUTES menu key to display the

ROUTES screen. Press the CURSOR PAD to select the route you want to follow, then press the GO menu key. The 958 displays the CHART screen with the nearest waypoint in the route selected, but you haven’t actually begun to follow the route yet.



•

•

•

From here, you can perform the following functions: select a starting waypoint or leg reverse the route start following the route

Selecting the starting point

Initially, the nearest waypoint is selected as the starting point of the route. You can press the CURSOR PAD select a different waypoint or route leg. To see a small or large area of the route, press the IN and OUT keys, respectively. If you decide not to follow this route, press the RETURN menu key to go back to the ROUTES screen.

Reversing the route

To follow the route in the opposite way of the route’s small directional arrows, press the REVERSE menu key. The direction of the route and the arrows will change from end to end.

Starting the route

To go directly to any selected waypoint in the route (the nearest one is the default), press the GO TO WAYPT menu key, then press the ENTER key. The 958 calculates a track line from your present position to the selected route waypoint.

If you want to start navigating along a route leg, rather than directly to a waypoint, select the leg by moving the cursor


Chapter 8 - Understanding Waypoint/Route Navigation onto the leg, then press the FOLLOW LEG menu key, then press the ENTER key. In this case, your cross-track error starts at a number that’s your distance from that leg. The leg you’re currently navigating along is displayed with arrows indicating your direction of travel; other legs are displayed with fewer arrows.

Restarting the course line

When travelling from one waypoint to another, you may find you’ve gone off your planned course line. Maybe you avoided an obstacle or drifted slightly off-course. Whenever you’re off-course, you can get back by one of two methods:

•

• after passing the obstacle, you can steer your vessel back to the original course line by using the cross-track error display, and just continue to the waypoint (Course 1 below) after passing the obstacle, if you don’t have to go back to your original course line, you can go right to the next waypoint by using the 958’s restart function (Course 2 below)

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Figure 5: Restarting the course line




To restart your course line from your present position, display either the NAV LOG screen (by pressing the NAV LOG key) or the CHART screen’s vessel mode (by pressing the CHART key, then the VESSEL key), then press the RESTART menu key and the ENTER key. If you’re on the chart screen, you must first press the vessel key

The 958 recalculates the course line to go from your present position directly to the next waypoint, and resets your cross-track error to zero.

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9

Using the Nav Log

Introducing the nav log . . . . . . . . . . . . . . . . . . . . 122

Changing your trip . . . . . . . . . . . . . . . . . . . . . . . . 123

Stopping and restarting navigation . . . . . . . . 124

T his chapter explains the 958’s nav log function, which gives you a quick and easy way to check your progress during your trip, and make changes to it while you travel.


Chapter 9 - Using the Nav Log

Introducing the nav log

The 958’s nav log helps you plan and log your trip. The nav log provides three main functions:

•

•

• to display your progress along your trip to let you easily change the rest of your trip (add waypoints to a route, or reverse the entire trip) to allow you to sequence to the next leg, if you’ve chosen manual waypoint sequencing (see ”Switching waypoints manually or automatically” starting on page 169)

The nav log contains the series of waypoints that you follow along your route, and displays them in sequential order. When you navigate to these waypoints, or along an already stored route, the series of waypoints is copied into the nav log, which acts as a kind of “scratch pad” to monitor your progress. You can change the nav log’s route in any way you want without affecting the original route, which remains safely stored in the

958.

To see the waypoints you’re currently navigating along, press the NAV LOG key at any time.

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The NAV LOG screen shows the list of waypoints, the length and bearing of each leg, and the direction of your next trip leg.

Press the CURSOR PAD to scan the waypoints in the list. To display either a waypoint’s description or its estimated time of arrival (ETA), press the NAME/DESC or NAME/ETA menu key.

For waypoints you haven’t passed yet, the times of arrival


Chapter 9 - Using the Nav Log shown are estimates based on your current speed. For waypoints you’ve already passed, actual times of arrival are shown . The 958 updates this information as you travel.

NOTE:

Estimated times are just estimates, which may be inaccurate if your SOG changes, either intentionally or by passing through varying currents.

Your ETA at the last waypoint is shown at the top of the screen. A darkened arrow connecting the right ends of two waypoint boxes indicates you’ve completed that leg of the trip.

Changing your trip

Adding waypoints to your trip

You can add waypoints to your trip at any time:

1. On the NAV LOG screen, press the APPEND WAYPT menu key to display a chart view of the trip waypoints on the APPEND WAYPT screen.

2. Press the CURSOR PAD to select the desired waypoint.

3. Press the SELECT WAYPT menu key, then press the

ENTER key to add the waypoint to the nav log. Note: Any waypoints added in this manner aren’t permanently added to the original route stored in the 958. To permanently change a route, you must use the 958’s edit-route function. (For details, see ”Editing a route” starting on page 100.)

4. Repeat these steps for any more waypoints you want to add.

NOTE:

If you go to a waypoint or along a route by using the 958’s GO TO function, the 958 automatically enters and organizes the waypoints in the nav log.

Reversing your trip

You can reverse your trip at any time. Pressing the REVERSE menu key on the NAV LOG screen lets you travel the trip in the opposite direction.


Chapter 9 - Using the Nav Log

Stopping and restarting navigation

Stopping navigation

Whenever you press the nav log’s STOP menu key, the 958 stops navigating, and won’t display distance and bearing to waypoints or ETA or ETE.

Restarting navigation

You can restart navigation along any leg or to any waypoint of the trip. On the NAV LOG screen, move the cursor arrow to highlight the waypoint or leg. When you select a waypoint, a triangle points to the waypoint. When you select a leg, an arrow points from the first waypoint to the second. Press the

RESTART menu key.


10

Understanding Radar Functions

Understanding how radar works . . . . . . . . . . 126

Displaying and controlling radar . . . . . . . . . . . 126

Turning radar on and off . . . . . . . . . . . . . . . . . . 128

Overlaying radar on the chart . . . . . . . . . . . . . 128

Changing scale and rotation . . . . . . . . . . . . . . . 130

Using the main radar keys . . . . . . . . . . . . . . . . . 132

Using the adjust radar keys . . . . . . . . . . . . . . . . 134

Using the radar markers keys . . . . . . . . . . . . . . 137

T his chapter first describes radar briefly, and then explains how to display, control, and adjust the 958’s radar.


Chapter 10 - Understanding Radar Functions

Understanding how radar works

The word “radar” is an acronym for “Radio Detecting and

Ranging.” A radio transmitter sends out a very short microwave pulse, and then a receiver listens for that signal’s echo when it’s bounced back from something in its path

(called the “target”). The returning signal is processed by a computer to determine its relative distance, position, and bearing. This information is graphically displayed on a screen for you to see. The target might be other boats or ships, navigational markers, flocks of birds, land masses, or some other object. By knowing how long it takes for a signal to return, the distance to a target can be determined. As the radar antenna scans through a 360-degree rotation, it shows where the target is relative to your position. By repeated scans of a target such as another vessel, you can see where that other vessel is moving. For more information about how radar works, see ”Introducing radar” starting on page 187.

Displaying and controlling radar

To display radar alone on a full screen:

1. Press the CHART key to display the CHART screen.



2. Press the SPLIT key to display the SELECT A SPLIT

SCREEN menu.

3. Press the RADAR key to view the radar:


NOTE:

If you haven’t turned the radar transmitter on, you’ll see a blank screen or a residual echo. To turn on the radar transmitter, see ”Turning radar on and off” starting on page 128.

Among other items of information, the radar image includes:

• A north indicator to show the direction of True or

Magnetic North (see ”Choosing magnetic variation” starting on page 169)

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• The current radar scales, shown by the number in the upper left corner of the radar image, labelled RR (range rings). This number indicates the spacing between the range rings.

• A dashed white heading line, which appears when your vessel is moving. This line indicates heading, not course-over-ground, and can be used to compare the radar presentation with the view in front of the vessel. It continues to the edge of the screen.

For information about rotating and scaling the radar, see

”Changing scale and rotation” starting on page 130.

Turning radar on and off

When you power up the Northstar 958, radar is off. This is a safety feature.

To turn radar on, you must turn on the radar transmitter:

1. Press the SPLIT key to show radar.

2. If needed, press the CONTROL key until it indicates

RADAR .

3. Press the ADJUST RADAR key.

4. Press the NEXT key until you see page 2 with the RADAR

TX key.

5. Press the RADAR TX key until it indicates ON .

6. Press the DONE key.

Your radar is now on and operational.

Your radar turns off automatically whenever you power off the

958 or whenever you turn off the radar transmitter (by pressing the RADAR TX key to indicate OFF ).

Overlaying radar on the chart

To overlay radar on the chart:

1. Press the CHART key to display the CHART screen.



2. Press the CHART SETUP key to display the CHART SETUP screen:

3. Press the RADAR OVERLAY ON key to overlay radar on the chart:



4. To control the radar overlay from the CHART screen (for example, to adjust its transparency), press the CONTROL key so that it shows RADAR :

5. When you overlay a radar image on a chart, you can choose whether the radar should be opaque (the chart doesn’t show through) or transparent (the chart shows through faintly):

•

• Press the ADJUST RADAR key, then access page 2 by pressing the NEXT key if needed.

Press the FADE key to select off (no transparency), 1, or 2 (maximum transparency).

If you power off the 958, when you turn it on again, the chart still has a radar overlay.

To remove the radar overlay, press the CHART SETUP key, then press RADAR OVERLAY OFF .

Changing scale and rotation

Changing the scale

To change the radar’s scale, press the IN key to zoom in

(smaller area, more detail) and the OUT key to zoom out (wider area, less detail), as described in ”Zooming in and out” beginning on page 41.



If there’s no radar overlay on the chart, you scale the chart and radar separately; zooming in on the chart, for example, has no affect on the radar. If the CONTROL key indicates RADAR , you’re zooming the radar; if it indicates CHART , you’re zooming the chart.

However, if the chart has a radar overlay and you zoom in on the chart, radar changes to match. Changing the chart’s scale changes the radar; and changing the radar’s scale changes the chart, even if the chart isn’t visible.

Changing the rotation

To change the radar’s rotation, press the ROTATE key repeatedly until it indicates the rotation you want; you have the same options as for a CHART screen (see ”Rotating the chart” starting on page 49).

The rotation of the chart and the rotation of the radar interact under certain circumstances, as described in the table below.

Assume that the chart and radar are both north-up at the start.

If the CONTROL key indicates RADAR , you’re rotating the radar; if it indicates CHART , you’re rotating the chart.

If the CHART screen’s in ...

And the radar image is ...

Overlaid on the chart Not overlaid

Browse mode The chart can’t rotate; but if you change the CONTROL

Vessel mode key to RADAR , the chart’s mode automatically switches to vessel (see below)

Chart and radar both rotate together, so if you change the radar to leg-up, the chart automatically changes to match (and vice versa)

The chart can’t rotate but the radar can rotate; so if you change the radar to leg-up, the chart doesn’t change (it stays north-up)

Chart and radar both rotate but separately; so if you change the radar to leg-up, the chart doesn’t change

(and vice versa)



Using the main radar keys

The main radar keys allow you to choose the split, control the radar, rotate the radar image, access a variety of further keys

(adjust radar and radar markers), and show more information:

Some of these keys have two parts: the function (such as

ROTATE ) and the current status of the function (such as

COURSE UP ).

To change the status:

1. Press the key to select the function (a small arrow appears next to the function).

2. Press the key again to select the status (a small arrow appears next to the status).

3. Press the key repeatedly until you access the status you want.

Choosing the split

Press the SPLIT key to view the SELECT A SPLIT SCREEN menu. Then choose the split you prefer from the following:

•

•

•

Press VIDEO to overlay video on the screen

Press the CHART key to see the chart only

Press the CHART|SOUNDER key to see the chart and sounder together



•

•

• Press the CHART|RADAR key to see the chart and radar together

Press the CHART|RADAR|SOUNDER key to see the chart, radar, and sounder together

Press the RADAR key to see the radar only

For details about split screens, see ”Controlling the screen” starting on page 48.

NOTE:

There’s less room on a split screen than on a full screen. For detailed viewing of the radar, choose a full screen.

Controlling radar

If you want to control the radar, the CONTROL key must indicate RADAR .

If necessary, press the CONTROL key repeatedly until it indicates RADAR .

Rotating the radar image

Press the ROTATE key repeatedly to set the screen rotation.

You can choose North up, course-up, heading-up, or leg-up.

Adjusting the radar

Press the ADJUST RADAR key to display the first of three pages of radar adjustments. For more information about using these keys, see see ”Using the adjust radar keys” starting on page 134.

Using the radar markers

Press the RADAR MARKERS key to display the first of three pages of controls for the 958’s range rings, bearings, electronic bearing lines (EBLs), variable range markers (VRMs), and guard zones. For more information about using these keys, see see

”Using the radar markers keys” starting on page 137.

Viewing more info

Press the MORE INFO menu key to display an “info bar” at the bottom of the screen. Each additional press of the MORE INFO key shows the following information:



•

•

•

• your vessel’s present Speed-Over-Ground ( SOG ),

Course-Over-Ground (COG), and heading.

your vessel’s distance ( DIST ) and bearing (BRG) to the current waypoint, if any your vessel’s position in lat/lon (or TDs, if enabled) the depth, water temperature, and Speed Through Water

(STW) reading from the sounder

Using the adjust radar keys

Press the ADJUST RADAR key to display the first of three pages of radar adjustments. Most of these adjustments correspond to conventional radar adjustments and are used in the same way.

Using the keys

The keys on each page have two or more parts: the upper part shows the function (such as RAIN CLUTTER ) and the lower part shows the status (such as MANUAL ). Some keys also have a middle part that shows a numerical value (such as 30 ).

To use a key:

1. Press the key once to select the function (a small arrow appears next to the function).

2. Press the key a second time to select the status (a small arrow appears next to the status).

3. Change the status by pressing the key repeatedly or by using the CONTROL PAD up and down arrow keys.

4. If a numerical value appears on the key (either in the middle position or as the status), you can change the value in two ways:

•

• Either press the CONTROL PAD up and down arrow keys

Or use the number keys on the KEYPAD to enter the quantity you want



Press the NEXT key to display the next page of adjustments.

Press the DONE key to return to the main radar menu keys.

The 958 comes with default factory settings that you can leave in place. If you turn off the 958, it remembers any changes you made to these adjustments.

Range Rider function

In many situations, manual adjustments provide better performance than the 958’s automatic settings. But the best manual settings are often different for each range. Northstar’s exclusive Range Rider function solves this problem for adjustments to sea clutter, rain clutter, and/or gain. Manually entered adjustments are stored separately for each range and automatically applied when the range setting changes. The effect is a properly set adjustment for each range.

When you first use the radar, you may need to make many manual adjustments, until the 958 learns the optimum settings for each range. However, once the 958 learns the settings, the Range Rider setting may be preferable to either manual or automatic settings.

Adjust radar page 1

Press the keys to adjust the rain clutter, sea clutter, gain, and electrical interference.

The RAIN CLUTTER key controls the strength of the clutter echoes returned from rainfall or snow. You can set the rain clutter for manual adjustment (by you) or automatic adjustment (by the 958). If you’re adjusting the rain clutter manually, you can change the rain clutter value.

The SEA CLUTTER key controls the strength of the clutter echoes returned from the ocean surface. You can set the sea clutter for manual adjustment (by you) or automatic adjustment (by the 958) or automatic adjustment specifically for harbor areas (by the 958). If you’re adjusting the sea clutter manually, you can change the sea clutter value.



The GAIN key controls the strength of all echoes, and should be adjusted for a pleasing and useful image. You can set the gain for manual adjustment (by you) or automatic adjustment

(by the 958). If you’re adjusting the gain manually, you can change the gain value.

Certain types of interference (for example, from radar operated by other vessels) can be lessened by using the interference rejection filter. Press the INTERFERENCE REJECTION key repeatedly to select off, 1 (low), 2 (medium), or 3 (high).


Press the following keys to adjust the radar transmitter, the transparency (fade) of the radar overlay on a chart, the radar trails, and the visibility of echoes.

Press the RADAR TX key repeatedly to turn the radar transmitter on or off. the radar transmitter is automatically turned off every time you shut down the 958; therefore, you must turn the RADAR TX key to ON every time you power up the

958. Turning the transmitter off when it is not in use can save electrical power and allows you to work safely in the vicinity of the rotating antenna.

When you overlay a radar image on a chart, you can choose whether the radar should be opaque (the chart doesn’t show through) or transparent (the chart shows through faintly).

Press the FADE key repeatedly to select off (no transparency),

1, or 2 (maximum transparency).

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Trails on the radar image help you track the motion of moving targets. You can select the trail that appears at a target’s location. Press the TRAILS key repeatedly to turn the trails off completely or select a 15-second, 30-second, 1-minute,

3-minute, 6-minute, or continuous trail.

Press the EXPAND key repeatedly to turn echo expansion off or on. Select ON to make very small echoes appear larger and easier to see.




Press the following keys to adjust the tuning.

NOTE:

The following keys are password protected. For information about how to use the keys and how to enter the password, see the Northstar Radar

Installation Manual (part number GMRadarIM).

The ROUGH TUNE key tunes the radar for the strongest echoes.

The FINE TUNE key is hidden until you press the ROUGH

TUNE key. The FINE TUNE key refines the tuning adjustment.

Trigger delay is an installation adjustment used to compensate for variations in cable length and other factors.

The heading calibration matches the displayed radar heading with the actual heading of the vessel.

Using the radar markers keys

Press the RADAR MARKERS key to display the first of three pages of controls for the 958’s range rings, bearings, electronic bearing lines (EBLs), variable range markers (VRMs), and guard zones. Press the NEXT key to display the next page of adjustments. Press the DONE key to return to the main radar menu keys.

The 958 comes with default factory settings that you can leave in place. If you turn off the 958, it remembers any changes you made to these adjustments.

Radar markers page 1

These keys let you adjust the electronic bearing lines. Electronic bearing lines (EBLs) are markers that you can place on top of the radar image to aid in navigation and in keeping


Chapter 10 - Understanding Radar Functions track of your surroundings. The 958 uses two types of EBLs: fixed and floating.

The fixed EBL is a blue line from your present position (Point

“A”) to Point “B.” You can move Point B on the screen using the cursor pad as described below. At the end of the line, a blue circle called a variable range marker (VRM) surrounds the area of interest. Another VRM circle surrounds your vessel’s position.

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Figure 6: Electronic bearing line

The VRM at your position (Point A) is called VRM A. The VRM at Point B is called VRM B. You can change the size of each

VRM, to use it for measuring distances from Point A or Point B to any point of interest on the screen.

The floating EBL is a pink line between any Point A and any

Point B. It’s similar to the fixed EBL, except that Point A can also be moved to allow measuring distances between any two points on the screen. Again, there’s a variable range marker at each end of the line.

The following information about the EBL and the VRM appears on your screen:

• In the upper right-hand corner, you’ll see:

> The location of Point A or Point B (whichever point you selected)

> The ETE and ETA to Point A or Point B (whichever point you selected), assuming that your vessel is moving




• In the bottom right-hand corner, you’ll see the radius of the VRM(s). These numbers are color coded blue for fixed

EBL and pink for floating EBL.

• In the bottom left-hand corner, you’ll see the length of the electronic bearing line(s). These numbers are also color coded blue for fixed EBL and pink for floating EBL.

Press the following keys to adjust the electronic bearing lines.

Press the EBL key repeatedly to select the fixed or the floating

EBL. You can adjust only one EBL at a time.

Press the VISIBILITY key repeatedly to show or hide the EBL.

When an EBL is hidden, it is turned off; furthermore, you can’t use the EDIT key for that EBL. You select the visibility of each

EBL separately.

Press the EDIT repeatedly to select what part of the EBL is controlled by the cursor pad:

•

•

•

•

Point A—(floating EBL only) the position of one end of the

EBL

Point B—the position of the other end of the EBL

VRM A—the size of the VRM circle at point A

VRM B—the size of the VRM circle at point B

As you change Point A or B, the numbers in the upper right-hand corner of your screen change to show the new location of the point. Also, the numbers in the lower left-hand corner change to show the new length of the EBL.

As you change VRM A or B, the numbers in the lower right-hand corner of your screen change to show the new radius of the VRM circle.

Page 139



You can designate up to three areas that will cause an alarm if a radar echo is detected within the area. Each zone is bounded by an inner and an outer arc centered on the vessel, and by two straight lines extending outward from the vessel.

You can turn each zone on or off, change its size and location, and set the echo strength that will cause an alarm.

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Figure 7: Guard zone

The guard zone is displayed with red lines. Radar echoes within a guard zone are displayed in red.

Press the following keys to adjust each guard zone.

Press the GUARD ZONE key repeatedly to select zone 1, 2, or

3. You can adjust only one zone at a time.

Press the VISIBILITY key repeatedly to show or hide the zone.

When a zone is hidden, it doesn’t display and doesn’t alarm; furthermore, you can’t use the EDIT or TRIGGER LEVEL keys for that zone. You select the visibility of each zone separately.

You can change the location and size of each guard zone by moving Point A and Point B using the CURSOR PAD . Press the

EDIT key repeatedly to select the point you want to move.

Then press the CURSOR PAD to move the point and create an arc-shaped zone.



As you change Point A or B, the numbers in the upper right-hand corner of your screen change to show the new location of the point.

You may want to generate an alarm when an echo of a certain minimum strength occurs within the zone, indicating an object within the guard zone. Press the TRIGGER LEVEL key repeatedly to set the signal strength that causes an alarm: low, medium, high, or off (no alarm). You can set the alarm to be visual only (a white circle flashes to pinpoint the alarm) or both visual and audible (see ”Changing alarm settings” starting on page 152).

The alarm is temporarily disabled while you adjust the trigger level. It automatically restarts if a minute passes with no further adjustments. When you press DONE , the alarm is enabled.


Range rings are concentric circles around your vessel, that appear on the screen at fixed intervals. These rings are controlled by the radar and represent distance. You should be careful to note the spacing of the range rings. An object three rings away would be 1.5 nm miles from your vessel if range rings are 0.5 nm apart; however, it would be 15 nm from your vessel if range rings are 5 nm apart. The spacing of the range rings is shown in the upper left-hand corner of the radar image.

Press the following keys to turn the range rings on or off, and to change the bearings.

Press the RANGE RINGS key repeatedly to turn the range rings on or off.

Press the Bearings key repeatedly to display radar bearing digits as relative to the vessel heading, or as True bearings/

Magnetic bearings (see ”Choosing magnetic variation” starting on page 169).




11

Alarms, TideTrack, and Video Display

Understanding alarms . . . . . . . . . . . . . . . . . . . . . 144

Understanding TideTrack™ . . . . . . . . . . . . . . . . 158

Using the video display option . . . . . . . . . . . . . 160

T his chapter describes the 958’s alarms, TideTrack, and the optional video display.


Chapter 11 - Alarms, TideTrack, and Video Display

Understanding alarms

Alarms automatically alert you to certain situations, for example, when you’re approaching a waypoint, or entering an avoidance area, or when you’ve lost position fixes. The 958 displays its alarms in two different ways:

•

• as specific alarm icons on the display screens as alarm messages (with details about the alarm icon) on the ALARMS screen

Also, whenever an alarm icon appears on any screen, an audible alarm will sound if you’ve turned on the alarm audio.

Each alarm has a distinctive beep that’s based on Morse code.

If you’re choosing whether to keep the alarm audio on or off, remember that the audio beep may be a necessity when you’re unable to look at the display screen.

Understanding alarm icons

There are 18 possible alarm icons, depending on the particular alarm condition. For a detailed explanation of these alarm icons, see Table 6 on page 146.

Page 144

Figure 8: Alarm icons

Three of these icons—bottom, fish, and temp—will only appear if you’re using the echo sounder (fishfinder); for details, see the Northstar 490 Operations Manual (GM490) .

Two of these icons—radar guard and no radar data—will only appear if you’re using radar.


Displaying alarm messages


To display the alarm message associated with the icon, press the STAR key to display the ALARMS screen.

New alarm messages

The word NEW in the RECENT ALARMS box tells you that the alarm shown hasn’t been “cleared” yet (see “Clearing alarms” below). There may also be other uncleared alarms.

Recent alarm messages

The 958 keeps a record of the one most recent alarm from each main category (anchor, avoidance, communications, cross track, and waypoints). This lets you “browse” through the older alarm messages. Each successive press of the CLEAR

ALARM menu key will show you the most recent alarm message from each category.

Clearing alarms

Clearing an alarm means removing the flashing alarm icon as well as the word NEW from the display of that alarm on the

ALARMS screen. To manually clear an alarm (or to see other alarms that may need clearing), press the CLEAR ALARM key on the ALARMS screen.



There are two types of alarms:

•

• “Auto-clear” alarms - These automatically clear after the alarm condition disappears, or in some cases, after a short time-out period (typically about 10 seconds). Most alarms are auto-clearing; however, they can also be manually cleared, if desired.

Alarms that require manual clearing - These will stay onscreen until you clear them on the ALARMS screen.

All of the 958’s alarms are described in Table 6 below.

NOTE:

The following abbreviations are used in Table 6.

For alarm message, ‘NAME’ = name of waypoint.

For “must be cleared,”, N = no, Y = yes

Table 6: 958 alarms

YOUR ANCHOR

MAY BE DRAGGING

Vessel has moved outside the radius limit set in the ANCHOR alarm. This alarm is shown only if you’ve turned it on at the

ALARMS screen and you have pressed the DROP ANCHOR key.

Does not time out.

Y



Table 6: 958 alarms (continued)

YOU’VE ARRIVED

AT WAYPT: ‘NAME’

Vessel has entered the arrive radius of an active waypoint. This alarm is shown only if you’ve chosen manual waypoint switching, or when you’re navigating to a single waypoint.

Within 10 seconds.

N

YOU’VE ENTERED

AVOID ZONE

Vessel has entered the warning radius of an avoidance waypoint. This alarm is shown only if you’ve turned it on at the

ALARMS screen.

Does not time out. Y

Vessel has switched to the next leg of the route.

Within 10 seconds.

N

NOW NAVIGATING

TO WAYPT: ‘NAME’




YOU’RE CLOSE TO

WAYPT: ‘NAME’

Vessel is within 900 feet of entering the arrive radius of an active waypoint.

Within 10 seconds. N

CROSS-TRACK

LIMITS EXCEEDED

Vessel has exceeded the off-course limit set in the CROSS TRACK alarm. This alarm is shown only if you’ve turned it on at the ALARMS screen.

Does not time out. N

You’ve powered-up the 958 while already in demo mode


!!DEMO MODE IS

ON!!




NO WAAS/DGPS

BIG JUMP IN GPS

POSITION

DGPS or WAAS corrections were previously used, but are now temporarily unusable. This alarm is shown only if you’ve turned it on at the ALARMS screen and

GPS or Phantom loran fixes are being used.


Your displayed GPS position suddenly

“jumps” an unreasonable amount based on the vessel’s speed.


NO GPS POSITION

FIX

GPS position fix is unavailable and GPS or Phantom loran is the chosen position source. This alarm is delayed for three minutes at power-up.

Does not time out.

N




GPS

COMMUNICATION

FAILURE

The 958 hasn’t received any messages from the GPS receiver pod for over 30 seconds.


Position fix from an external loran receiver is unavailable and external loran is the chosen position source. This alarm is delayed for three minutes at power-up.

Does not time out.

N

NO LORAN

POSITION FIX

LORAN

COMMUNICATION

FAILURE

The 958 hasn’t received any messages from the external loran receiver for over

30 seconds.

Does not time out.

Y




YOU’VE PASSED

WAYPT: ‘NAME’

Vessel has passed abeam of the active waypoint — without entering the arrive radius. This alarm only appears if there are NO future waypoints, or if waypoint switching is manual.

Within 10 seconds.

N

BLINK, CYCLE or LOW SNR detected in the external loran used as the position source.


POOR LORAN

SIGNALS

BOTTOM

COLLISION!

Sounder alarms ( only shown on the 958 if sounder is enabled )

Echo sounder detects that the seabed is higher than the specific limit you’ve set

Within 20 seconds after the seabed becomes lower than the limit set.

N

Radar alarms ( only shown on the 958 if radar is enabled )




An object enters the guard zone.

Does not time out.

Y

RADAR GUARD VIO-

LATION

The 958 hasn’t received radar data for several seconds.

When new data comes in.

N

RADAR DATA NOT

AVAILABLE

Changing alarm settings

You can manually adjust four of the 958’s alarms:

•

•

•

• anchor alarm cross track arrive radius

DGPS alarm




You can also turn the alarm audio on or off for all of the 958’s alarms

.

Alarm audio

You can turn the alarm audio on so that the 958 will beep when any alarm goes off, or you can turn the audio off completely so that you’ll only see alarm icons and messages displayed on the screen:

1. Press the CURSOR PAD to select ALARM AUDIO, then press the EDIT ALARM menu key.

2. Press the CURSOR PAD to display OFF or ON , then press the ENTER key.

Anchor alarm

The anchor alarm will signal if your vessel moves a certain distance from the position where you pressed the DROP

ANCHOR key. You can turn the anchor alarm on or off, and set the anchor drag distance. The default setting is 0.20 nautical miles (about 1200 feet). You can set the anchor alarm to as little as .01 nm.

Note: Turn off the anchor alarm before you intentionally move away from the anchor-drop point.

To set the anchor alarm:

1. Press the DROP ANCHOR menu key where you’ve dropped the anchor. A waypoint named ANCR is created at this location.

2. Press the ENTER key at the question window.

3. Press the CURSOR PAD to highlight ANCHOR ALARM, then press the EDIT ALARM menu key.

4. Press the CURSOR PAD to turn the alarm to ON .

5. To set the distance your vessel can normally be expected to move on its anchor chain, press the CURSOR PAD right, and use the KEYPAD to enter the distance. Be sure

Page 153

Chapter 11 - Alarms, TideTrack, and Video Display to subtract a safety factor to allow for GPS or loran inaccuracy, then press the ENTER key.

Cross-track alarm

The cross-track alarm will signal if your vessel moves beyond a certain distance from the desired track line. You can turn the cross-track alarm on or off, and set the distance from the track line. The default setting is 0.10 nautical miles (about 600 feet).

You can set the cross track to as little as 0.01 nm (about 60 feet).

To set the cross-track alarm:

1. Press the CURSOR PAD to highlight CROSS TRACK , then press the EDIT ALARM menu key.

2. Press the CURSOR PAD to turn the alarm to ON .

3. To set the cross-track distance limit, press the CURSOR

PAD right, and use the KEYPAD to enter the distance, then press the ENTER key.

Arrive radius

The arrive radius is a circle around your current active waypoint. The default setting for the radius is 0.20 nautical miles, or about 1200 feet. You can set the radius to as little as

0.01 nm.

There are two alarms triggered by the arrive radius. If you’re following a route and have chosen automatic waypoint switching, entering the radius makes the 958 switch to the next leg and display the CHANGING alarm icon. If there are no more waypoints in the route, or if you’ve chosen manual waypoint switching, then entering the radius triggers the arrive alarm.

Note: Automatic waypoint switching will also occur if you cross the perpendicular at the end of the current leg.



To set the arrive radius:

1. Press the CURSOR PAD to highlight ARRIVE RADIUS , then press the EDIT ALARM menu key.

2. To set the distance around waypoints, use the KEYPAD to enter the distance, then press the ENTER key.

DGPS alarm

The DGPS alarm will signal if you were using GPS or Phantom loran fixes, but valid, usable beacon or WAAS differential corrections haven’t been received within the time limit you’ve specified in the DGPS data time-out setting. To adjust this setting, see ”Choosing a DGPS corrections time-out” starting on page 176.

To turn on the DGPS alarm, press the CURSOR PAD to highlight DGPS ALARM , then press the EDIT ALARM menu key. Press the CURSOR PAD to turn the alarm to ON , then press the ENTER key.

Setting alarms to honk

You can set the 958 to honk, in addition to the beep, if a honker has been connected to pin #14 on the interface connector. Once you set the anchor alarm to honk, a continuous honking sequence begins when:

• your vessel moves outside the specified anchor-alarm radius

- or -

• the navigation source (for example, GPS) becomes unavailable, so that it’s unsure if you’re inside the radius

To set the anchor alarm to honk:

1. On the ALARMS screen, press the CURSOR PAD to highlight HONK OUTPUT , then press the EDIT ALARM menu key.



2. Press the CURSOR PAD to select ANCHOR ALM.


4. Set the ANCHOR ALARM to ON if it’s currently set to OFF .

5. Press the DROP ANCHOR key.

If your vessel moves outside the anchor-alarm radius, then for the next 10 seconds, the anchor drag icon begins flashing and the alarm automatically beeps (you’ll hear the beeping only if you’ve set the ALARM AUDIO to ON ). The honk sequence then starts for a total of 3.5 minutes: 1 second of honking followed by 14 seconds of silence; 2 seconds of honking followed by 13 seconds of silence; 3 seconds of honking followed by 12 seconds of silence, and so forth, until the honking is up to 14 seconds followed by 1 second of silence.

This 3.5-minute honk cycle repeats forever until you manually clear the anchor alarm. This honk does not automatically clear under any conditions. To clear the alarm, press the STAR key to display the ALARMS screen, then press the CLEAR ALARM key. You may also want to set the anchor alarm back to the OFF setting.

Honking for all alarms

Instead of setting all alarms to only beep, you can set all alarms to honk. This honking starts simultaneously with any flashing alarm icons. After you set all alarms to honk, an alarm causes the 958 to emit a sound for half a second, followed by silence for half a second. This honking sequence stops when the alarms either automatically clear or you manually clear them.

To set all alarms to honk:

1. Press the CURSOR PAD to highlight HONK OUTPUT , then press the EDIT ALARM menu key.

2. Press the CURSOR PAD to select ALL ALARMS , then press the ENTER key.

3. Set the ALARM AUDIO to ON if it’s currently off.


Sound Type

Beep All alarms


Table 7 below describes how to set the anchor alarm and all other alarms to the desired audio.

Table 7: Beep and honk settings for all alarms

Setting(s) Description

Set ALARM AUDIO to ON The 958’s standard alarm beep.

Beep

Honk

Honk

Anchor alarm Set ALARM AUDIO to ON

All alarms

Set ANCHOR ALARM to

ON

Set ALARM AUDIO to ON

Set HONK OUTPUT to ALL

ALARMS

Anchor alarm Set

ON

ANCHOR ALARM to

Set HONK OUTPUT to

ANCHOR ALM

The 958’s standard alarm beep.

Alarm icons flash; the 958 simultaneously emits an output sound for half a second, followed by silence for half a second until the alarm is manually cleared.

The alarm icon flashes, and the alarm beeps (if the alarm audio is on), then after 10 seconds the honk sequence starts.



Understanding TideTrack

™

The 958 calculates tide information for any of over 3,540 NOS/

NOAA tide stations. To display this information, press the

STAR key until you see the TIDE TRACK screen.

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The entire U.S. coastline--including Alaska and Hawaii--is covered, plus many Caribbean islands and eastern and western

Canada. Tides can be displayed for any date up to the year

2010. Data is from the official tide-table predictions and should be as accurate as the printed tables. For more information about tides, see Tide Tables published by the NOS/

NOAA, Rockville, Maryland 20852.

The water height for any 24-hour period is displayed for the selected NOAA tide station.

The name of the selected tide station and the selected day are shown at the top of the screen.

The center of the screen shows a graphic representation of the tide height for the entire day. Maximum and minimum heights are shown as dashed horizontal lines labeled with the height in feet. Mean Lower Low Water (MLLW) is shown as a solid line near the bottom of the picture. A solid vertical line and arrow is positioned to show the tide level at the current time.

Just below the tide graph is the time scale, showing the local time (LCL) for each point, and (if the station is in a different time zone) the time at the tide station (TID).



At the bottom of the screen, the times of the day’s high and low tides are shown for that location, along with the tide height at the present time.

Choosing a nearby tide station

You can choose from any of the nine tide stations closest to your present position.

1. On the TIDE TRACK screen, press the CONFIGURE menu key.

2. Press the CHOOSE CLOSEST TIDE STATION menu key.

The 958 searches for the nine stations closest to your present position, and displays this list with the closest station at the top.

3. Press the CURSOR PAD to select the desired station, then press the ENTER key twice to display the tides for that station on the TIDE TRACK screen.

Choosing a tide station from the chart

You can choose a tide station by moving the cursor to any location along the U.S. coastline.

1. On the TIDE TRACK screen, press the CONFIGURE menu key.



2. Press the CHOOSE TIDE STATION FROM CHART menu key.

3. Press the CURSOR PAD to select the location for which you want tide information, then press the ENTER key to display a list of the nine tide stations closest to this cursor location.

4. Press the CURSOR PAD to select the desired station, then press the ENTER key twice to display the tides for that station on the TIDE TRACK screen.

Choosing a specific date

The TIDE TRACK screen displays tide information for today’s date. To display these tides for a different date:

1. Press the CONFIGURE menu key, then press the NEW

DATE menu key. The first digit of the current date flashes.

2. Press the CURSOR PAD to move to the month or digit you want to change. To change a digit, press that key on the KEYPAD . To change the month, press the CURSOR

PAD up and down.

3. When the date is correct, press ENTER twice to display the tides for the new date.

Using the video display option

If the 958 is connected to a video camera or other video source, you can display the image right on the 958’s display screens.

Video isn’t available on screens that require your input. Also, when info or question boxes are displayed, the video image will temporarily disappear until you acknowledge the question.

Turning the video image on and off

The video image can be turned on in either of two ways:

•

• On some screens, you access video by press the SPLIT key, then the VIDEO key.

On other screens, such as the STEERING screen, you access video with a single keypress ( VIDEO key).



• On a full ECHO SOUNDER screen, you must first press

MORE , then press VIDEO .

To turn the image off, press VIDEO again.

NOTE:

If the video source isn’t connected or isn’t working properly, color bars will be shown instead of a video image

Adjusting the video’s transparency

To adjust the video’s transparency, press the IN and OUT keys.

Pressing OUT lets you “see through” more of the video to the screen underneath; pressing IN will make the video more opaque. (If you’re displaying the CHART screen or 3D STEER screen or radar, the IN and OUT keys are reserved for zooming.

You must display a different screen, press IN or OUT , then return to those screens.)



Changing the video‘s size and location

Press the STAR key to display the VIDEO SETUP screen.

To change the size of the image, press a number from 1 to 9 on the KEYPAD . To move the image around on the screen, press the CURSOR PAD .


12

Setting Up Your 958

Changing your display settings . . . . . . . . . . . . 164

Changing your navigation settings . . . . . . . . . 167

Changing your receiver settings . . . . . . . . . . . 172

Changing your port settings . . . . . . . . . . . . . . . 177

Setting up the sounder . . . . . . . . . . . . . . . . . . . . 177

Setting up radar . . . . . . . . . . . . . . . . . . . . . . . . . . . 177

Displaying manufacturer’s information . . . . 178

Changing the time zone . . . . . . . . . . . . . . . . . . . 182

T his chapter explains the various options for changing how the 958 displays information, computes navigation data, and communicates with other devices. You can change each option at any time according to your specific needs.


Chapter 12 - Setting Up Your 958

Changing your display settings

To access the 958’s display options, press the STAR key until you see the OPTIONS/SERVICE INFO screen.

Press the DISPLAY OPTIONS menu key to access the DISPLAY

OPTIONS screen.

Page 164

Changing the settings

To change any of the options (explained in detail on the following pages), select the option by pressing the CURSOR

PAD to move the arrow at the left of the screen, then press the

EDIT menu key. The selected option flashes, waiting for you to change it using the CURSOR PAD or the KEYPAD . Once you’ve made the change, press the ENTER key, or press the

CLEAR key to cancel the change.


Choosing rhumb line or great circle calculations


You can set the 958 to calculate the distance and initial bearing to your intended destination along either a great circle route or a rhumb line.

The shortest distance between any two points on the surface of a sphere is called a great circle route. It appears as a curved line on a Mercator chart.

Rhumb line navigation maintains a constant true direction to your destination (seen as a straight line on a Mercator chart), but is a somewhat longer route to travel over great distances than the great circle calculation. Rhumb line is the 958’s default method of calculating distance and bearing to waypoints.

Great circle and rhumb line are virtually the same if the start and end points are closer than 100 nm. You can approximate a great circle using a series of shorter rhumb lines.

CAUTION!

Regardless of your selection, your cross-track error (including the steering indicator and autopilot output) is always calculated from a rhumb line, and the route lines on the chart are rhumb lines.

Choosing distance and speed units

You can set the 958’s display of distances and speeds to any of the following units of measurement:

•

•

• nautical miles and knots (nm/knots) kilometers and kilometers per hour (km/kph) statute miles and miles per hour (mi/mph)

This option also sets whether cross-track and distance-to-waypoint information on the STEERING and 3-D

STEER screens is displayed in feet or meters (the km/kph setting will display meters).



Choosing a 12- or

24-hour clock

You can set the time of day to either a 12- or 24-hour format.

The option you select here affects all of the 958’s time-related displays, including high and low tides, sunrise/sunset, and

ETA.

Choosing lat/lon precision

You can set the precision of the 958’s latitude and longitude displays to either degrees, minutes, and seconds (two decimal places, or .XX), or to degrees, minutes, and thousandths of minutes (three decimal places, or .XXX).

Choosing the number of saved waypoints

When you press the SAVE key, the 958 automatically assigns a sequential waypoint number (such as –S001–) to each point stored. When this number is the same as the number you set in the MAX SAVED WAYPT option, the 958 restarts at the number 1, and overwrites the old saved waypoint previously designated number 1. For many applications, you may want to set this maximum number to a small value, such as five or ten, as long as you promptly rename any saved waypoints you want to save permanently—before they’re overwritten by the

958.

To change this option, press the EDIT menu key. Using the

KEYPAD , enter the value you want—up to a maximum of

199—and press the ENTER key. For one- or two-digit values, enter zero as the first digit(s). The factory default setting is 100 saved waypoints.

Entering a personalized owner’s message

To provide your 958 with a substantial measure of theft protection, you can enter a personalized owner identification message using an four-digit access code. Northstar notifies you and confirms this code only when you return your product registration card. Once you’ve received your registered owner-access code, you can enter your individual owner ID message:

1. After selecting the OWNER’S MESSAGE option, press the

EDIT menu key. A question window appears, asking you to enter your password.



2. Enter the access code from your Northstar owner’s card, then press the ENTER key. The first character block of the owner’s message flashes.

3. Enter the message (up to two lines) you want to see when you power-up the 958, then press the ENTER key.

Your message can be changed only by entering your access code number and repeating the above procedure.

The 958 gives you three attempts at entering the correct access code; after that, all operations freeze, requiring you to turn power off, then turn it back on again to resume functioning.

Changing your navigation settings

To access the 958’s navigation options, press the STAR key until you see the OPTIONS/SERVICE INFO screen.



Press the NAVIGATION OPTIONS menu key to access the

NAVIGATION OPTIONS screen.


To change any of the options (fully described in the following pages), select it by pressing the CURSOR PAD to move the arrow at the left of the screen, then press the EDIT menu key.

The selected option begins to flash, waiting for you to change it using the CURSOR PAD or the KEYPAD .

Choosing a navigation source

The 958’s position displays and waypoint navigation are based on position information that it obtains from any one of the following navigation sources:

•

•

• GPS - choose this for GPS and WAAS

Phantom Loran - choose this if you want to see your position displayed as loran TD’s (the 958 calculates Phantom

Loran coordinates from the GPS coordinates) external loran choose this if a loran receiver is connected to the 958

NOTE:

If your 958 is connected with an optional external radiobeacon differential receiver, differential GPS corrections will automatically be used even if you select Phantom Loran.



NOTE:

This option also includes a setting for demo mode. For instructions on demo mode, see ”Using demo mode” starting on page 14.

Choosing magnetic variation

Compasses naturally point to the magnetic north pole, which is several hundred miles from the Earth’s geographic north pole.

The difference between the angles to the two poles is known as magnetic variation . The 958 provides the option of choosing from:

•

•

• true—0º automatic—the 958 calculates variation automatically according to your location manual—from 0º to 180º, East or West

True bearings are usually required when using a gyrocompass.

The factory default setting is automatic, to coincide with a magnetic compass. Your navigation charts indicate the approximate magnetic variation for each area. Under most conditions, you’ll want the 958 to calculate the variation automatically for your position, since the automatically calculated variation usually is entirely adequate.

The manual setting (1º to 180º) is available when the display must match an older or less accurate chart, or in remote areas

(such as above 70º north latitude) where the 958’s variation calculations can be significantly off.

Switching waypoints manually or automatically


You can set the 958’s waypoint switching to:

• automatic - the 958 automatically switches to the next waypoint upon arrival at each waypoint

• manual - you manually switch to the next waypoint

When set to automatic, the 958 displays the new distance and bearing information for the next waypoint when you arrive at the previous one. It immediately stops navigating when you pass a lone waypoint or the last waypoint in a route.

NOTE:

For instructions on changing the waypoint arrival distance, see ”Arrive radius” starting on page 154.

Page 169


You may want to switch waypoints manually if you’re maneuvering around a waypoint in search of a lobster trap, or trying to find a buoy in a thick fog. Manual switching lets you keep a constant display of distance and bearing information for the particular waypoint you’re using until you tell the 958 otherwise. With manual switching, you manually change to the next waypoint every time you arrive at the current waypoint: Press the NAV LOG key, select the next leg or waypoint if necessary, press the RESTART menu key, then press the ENTER key.

Choosing a geodetic datum

Different parts of the world use various models for lat/lon coordinates on their charts. Each model is called a datum. The

958’s geodetic datum option contains all referenced datums, according to Defense Mapping Agency publications.

You should always be sure that the datum the 958 uses matches your Nav-Chart cartridge. All Navionics charts for the last few years use WGS84, which is the 958’s default. A few old charts from areas such as South America have other datums.

Contact Navionics for more information. If you choose a datum other than WGS84, an offset will be applied, but only to the GPS lat/lon of your vessel’s position. The vessel will be moved on the chart, but not waypoints, routes, or track points.

To change the datum reference, on the NAVIGATION OPTIONS screen, select the GEODETIC DATUM option and press the

EDIT menu key, then press the CURSOR PAD up and down to scan through the alphabetic listing. When you see your choice, press the ENTER key. For a list of the 958’s available datums, see Appendix C at the back of this manual.

NOTE:

You can specify a different datum for the 958’s output ports than the one set for the positional display. For instructions, see the Northstar 958

Installation Manual (part number GM958IM).


Choosing the cross-track scale


You can set the CROSS-TRACK FULL SCALE option to suit your particular needs—whether you’re navigating out in open water or trying to maneuver in a tight channel. Cross-track scale is the total left-to-right distance shown on the STEERING and 3D

STEER screens. For example, a cross-track full scale setting of

1,000 feet displays 500 feet on either side of your track line.

When setting the cross-track full scale, your choices depend on the distance and speed units that you’ve set on the

DISPLAY OPTIONS screen. The relationship between the distance and speed units and the cross-track scale setting is described in the table below. (To change the distance and speed units, see ”Changing your display settings” starting on page 164.)

Table 8: Cross-track scale options

Dist/speed units setting

If... you choose MI/MPH

If... you choose NM/KNOTS

If... you choose KM/KPH

Cross-track full scale setting

Then... you can choose among

1000 FT, 2000 FT, or ½ MI


1000 FT, 2000 FT, ½ NM


200 M, 1KM, 2KM

To change the cross track full scale setting, on the

NAVIGATION OPTIONS screen, choose the CROSS TRACK

FULL SCALE option and press the EDIT menu key. Press the

CURSOR PAD to see the choices, then press the ENTER key to make your selection.

Changing the steering precision


The STEER DIST PRECISION option adds precision to the distance-to-waypoint and cross-track error displays on the

STEERING and 3-D STEER screens. For example, using the

“normal” setting will display the distance-to-waypoint in hundredths of miles or kilometers. However, if you change the setting to “high,” the distance-to-waypoint and cross-track error are displayed in feet or meters—when you’re under one mile or kilometer from the destination waypoint.

Page 171


Changing your receiver settings

To access the 958’s receiver options, press the STAR key until you see the OPTIONS/SERVICE INFO screen.

Page 172

Press the RECEIVER OPTIONS menu key to access the

RECEIVER OPTIONS screen.




To change any of the options (fully described in the following pages), select it by pressing the CURSOR PAD to move the arrow at the left of the screen, then press the EDIT menu key.

The selected option begins to flash, waiting for you to change it using the CURSOR PAD or the KEYPAD .

Choosing a speed averaging

When you’re using uncorrected GPS, you may see that your

Speed-Over-Ground readings, which are obtained from the

GPS satellites, are slightly erratic, varying by up to several knots. The 958’s GPS speed averaging function can help steady these readings. This function lets you select the time over which your speed is averaged, with choices between two and ten seconds. Averaging can also be turned off for the quickest possible reaction time. You can change the speed averaging value at any time without affecting other navigation functions.

Shorter averaging times provide a faster display of speed but with less accuracy. A longer averaging time is useful at lower speeds when you require the highest accuracy, such as when you want to trawl at a certain optimum speed. In this case, you’ll see a steadier, more accurate display that changes more slowly.



Choosing beacon frequency and baud rate

Differential corrections are invaluable for navigating in narrow or congested areas, such as ports and waterways, or whenever you require extreme accuracy in order to locate a precise area

(retrieving lobster pots, returning to a diving spot, and so on).

You can interface with 958 with an optional external Northstar beacon receiver. This receiver takes corrections broadcast by shore-based marine radiobeacons situated along most of the

U.S. coastline, then the 958 uses these corrections to improve its position accuracy to four meters or better—with one to three meters accuracy common. This two-channel receiver automatically tunes to the appropriate differential frequency as you move from one differential coverage area to another, or as weather conditions change. The receiver constantly evaluates the quality of the radiobeacon signals, selecting only the best station. As you travel, the receiver will switch to another frequency automatically as conditions require.

Automatic mode

Automatic mode can usually be used for all applications. The

958 enters automatic differential mode as soon as it receives corrections, and requires no further supervision of differential operation. It maintains automatic operation by using two independent receiver channels. Channel 1 tracks the best available differential signal (the one with the lowest data error rate) and sends the demodulated DGPS corrections to the unit’s GPS receiver. Channel 2 continuously scans the entire differential frequency band (283.5 to 325kHz), locating and measuring received DGPS differential signals. The 958 then stores this information as a DGPS differential “directory” in its battery-powered memory.

If the signal that’s received and monitored by Channel 1 degrades for any reason (such as bad weather between your vessel and the transmitter), the 958 tries to select a better frequency from the directory it has compiled. This function allows it to switch to the best differential signal before your

GPS accuracy is affected negatively.



Manual mode

Although the need is rare, you can manually override automatic mode at any time by issuing tuning commands using the 958’s KEYPAD . In manual mode, the differential receiver outputs its corrections only from the selected station.

To manually choose a differential station, you must select the frequency of the desired station:

1. On the RECEIVER OPTIONS screen, highlight the BEACON

FREQUENCY option and press the EDIT menu key.

2. Change the settings from AUTO to MANUAL.

A differential transmitter frequency appears to the right of the word

MANUAL.

3. Press the CURSOR PAD right to highlight the digits you want to change. Enter the appropriate frequency—any value between 283.5kHz and 325kHz—and press the

ENTER key.

NOTE:

You can also manually set the baud rate (the transmitter’s data transmission speed) for the selected differential frequency. H o wever,

Northstar strongly recommends leaving the setting at AUTO .

BEACON BAUD RATE

NOTE:

The 958 can manually control a non-Northstar external differential receiver as long as the receiver supports the MX50R control protocol.

Check the manufacturer’s instructions to see they support this control protocol.

Setting differential operation


The 958’S differential operations setting has four options for differential information:

•

• auto - the 958 prefers WAAS differential corrections, but will automatically switch to radiobeacon differential corrections if WAAS is not available or less accurate and if the 958 is connected to an optional external radiobeacon receiver disabled - the 958 doesn’t use any differential corrections, only GPS

Page 175


•

• radiobeacon - the 958 will use radiobeacon differential if it’s connected to an optional external radiobeacon receiver

WAAS - the 958 will use WAAS differential corrections

Choosing a DGPS corrections time-out

The DGPS data timeout setting determines how long the 958 will continue to use old DGPS corrections if no new corrections are received due to bad weather, extreme distance from beacon, etc.

Under normal operating conditions, you should set the time-out to one minute (the factory default) to guarantee the best accuracy. A time-out of 30 seconds or less is often too short and can cause intermittent problems. Generally, one minute provides good navigation accuracy, and is best left unchanged.

In bad weather—and if you can tolerate a minor loss of accuracy—you can increase the value up to a maximum of four minutes, which lets the 958 ignore the occasional outage of differential reception.

Regardless of the setting, if the time-out period ends without any new corrections, the 958 goes back to standard GPS navigation; displays the OLD CORRECTIONS status message on the DGPS STATUS screen; and displays the DGPS LOST alarm. DGPS will automatically resume when the 958 receives valid corrections.

Adjusting satellite elevation

The LOWEST SAT ELEVATION option is used mainly for technical applications, in which the 958 must track all visible satellites regardless of how low they are on the horizon. In other instances where high-precision fixes are necessary, you can change this setting to “hide” any low satellites, thereby preventing their use as sources of GPS position information, and avoiding potential errors.

This option is adjustable from 0° to 25°, in 5° increments, but

Northstar recommends leaving this option at the factory setting of 10°.



Changing your port settings

You can interface the 958 directly to a variety of external equipment, such as the Northstar 490 “black box” for fishfinding, autopilots, depth sounders, PC’s, and so on. The

958’s ports meet the specifications of most navigation devices, providing you with a customized setup for practically any

NMEA 0183-compatible equipment.

The 958 is interfaced with other equipment through its data transmission ports: two NMEA ports (NMEA) and one auxiliary port (AUX). To see the wiring information, press the STAR key to display the OPTIONS/SERVICE INFO screen, then the PORT

SETUP OPTIONS key, then the WIRING INFO key.

For details about interfacing the 958, contact your local authorized Northstar dealer.

Setting up the sounder

For the sounder to work with the 958, you must set up the

958’s AUX port for fishfinding:


INFO screen.

2. Press the PORT SETUP OPTIONS key.

3. Set the AUX PORT option to “490,” then press the ENTER key.

4. To enable this setting, turn the 958 off and back on again.

For instructions on setting up and using the sounder, see the

Northstar 490 Operator’s Manual (GM490).

Setting up radar

For radar to work with the 958, you must connect the RBOX to the 958’s Port 2 and configure the port as described in the

Northstar 958 Radar Installation Manual (part number

GMRadarIM).



To set up Port 2 for radar:


INFO screen.

2. Press the PORT SETUP OPTIONS key.

3. Press the PORT 2 SETUP key.

4. Press the EDIT key.

5. Set the output format to “Radar” by using the CURSOR

PAD up or down keys.


Installing Software Updates

You can install current software updates by obtaining a

Navionics-style software update cartridge from Northstar or your local authorized Northstar dealer.

CAUTION!

Do not remove the card and do not turn the unit off while the update is in progress or your 958 system will be corrupted.


INFO screen.

2. Press the MORE key.

3. On the MORE OPTIONS/SERVICE INFO screen, press the

SOFTWARE UPDATE key.

4. On the SOFTWARE UPDATE screen, to install the update, follow the instructions on your screen.

Displaying manufacturer’s information

To see your 958’s serial number and hardware specifications, press the STAR key until you see the OPTIONS/SERVICE INFO screen.



958 serial number

The serial number is located in the SERIAL NUMBER field (and on the back of the 958).

958 software version

The current version of the 958’s operating software is located in the SOFTWARE VERSION field.

Beacon receiver software version

If your 958 is connected to an optional Northstar radiobeacon receiver, its software version will be displayed in this field.

Beacon receiver self-test

If your 958 is connected to an optional Northstar radiobeacon receiver, the receiver is automatically tested each time the 958 powers up. If all test parameters are met, the message PASSED is displayed in the BEACON RCVR SELF TEST field. If the differential receiver fails any of the test criteria, the 958 displays the message FAILED . In many cases, the failure is caused by an open or shorted antenna cable, which can be repaired in the field. If this isn’t the source of the failure, you may have to return the 958 to the factory for service.



GPS receiver software version

The software version of the GPS receiver is located in the GPS

RCVR SOFTWARE VERSION field.

GPS receiver self-test

The GPS receiver’s self-test message is displayed in the GPS

RCVR SELF TEST field. If the message FAILED is displayed, you may have to return the 958 to the factory for service.

Testing the 958’s keypad

A built-in keypad test lets you check the integrity of the 958’s keys.

This function works for all keys except PWR ,

BRIGHTNESS , SAVE , and MOB key (pressing SAVE or MOB during the keypad test saves a waypoint instead of testing the keys).

On the OPTIONS/SERVICE INFO screen, press the MORE key to display the MORE OPTIONS/SERVICE INFO screen. Press the

DIAGNOSTICS menu key, then the KEYPAD menu key.

Pressing each key identifies it on the screen.

Page 180

When you’re done, press and hold the CURSOR PAD up or down until the 958 displays the MORE OPTIONS/SERVICE

INFO screen again.


Using the ignore-door feature


To help protect the Nav-Chart cartridge (as well as the 958’s internal components) from water and salt spray, a switch in the

958’s cartridge door latch senses if the door is open or closed.

When open, the 958 won’t do the following:

•

• use or display information from the chart cartridge display the cartridge’s ID name or date information on the

CHART SETUP/STATUS screen

Essentially, when the door is open the 958 acts like there’s no cartridge installed.

If the door becomes damaged, or the latch sensor doesn’t work properly, you can bypass the safety feature by pressing the

MORE key on the OPTIONS/SERVICE INFO screen, then the

IGNORE DOOR key on the MORE OPTIONS/SERVICE INFO screen, then the ENTER key. The 958 will then let you use the cartridge as if the door was functioning properly.

CAUTION!

Leaving the cartridge door open may cause serious water damage to the 958’s internal components. If the door is damaged, you should return the 958 to the factory for repair.

The IGNORE DOOR command should only be used for short-term emergencies when the door won’t close properly.

The bypass stays in effect until you disable it or shut the 958 off. The next time you turn the 958 on, the IGNORE DOOR command won’t be in effect; you must re-invoke it by re-pressing the IGNORE DOOR menu key.

Using the LCD test key

This key is used for factory testing of the 958’s screen, and pressing it will display a blank screen. Press any function key to return to another screen.



Changing the time zone

Press the STAR key until you see the TIME OF DAY screen.

The time, date, local time zone, and time of today’s sunrise and sunset are shown.

In the center of the screen, the current time expressed as

“GMT” (Greenwich Mean Time) is displayed. Note that the day of the week in Greenwich, England may be different from the day in your local time zone (right screen, above).

To change the time zone used for the time display (for both this and other time displays), press the TIME ZONE menu key, and use the CURSOR PAD to select the desired zone and standard or daylight time. Press the ENTER key to use the new time zone.


Appendix A - Understanding GPS, WAAS, and

Radar

Introducing GPS and WAAS

What is GPS?

The nation’s Global Positioning System (GPS) was developed by the United States Department of Defense, and comprises 21 active satellites (with three additional spares) that encircle the earth with navigation information. The major advantage of

GPS over all other commercially available navigation systems

(including loran) is its all-weather, worldwide availability and absolute accuracy. Absolute accuracy is the ability of a navigation device to determine your actual latitude and longitude coordinates on the surface of the earth. Repeatable accuracy is the ability to return to a position whose coordinates you’ve previously recorded with the same equipment.

GPS has an absolute and repeatable accuracy of 20 to 30 meters (better than 100 feet) 95 percent of the time, according to the U.S. government. This means that you can expect to be within 100 feet of your intended position 95 percent of the time, and beyond that area approximately five percent of the time.

When they developed GPS, the Department of Defense included a system of built-in errors, called Selective

Availability (SA), which they introduced as a national defense strategy to intentionally degrade the GPS solution. The DOD wanted to avoid the possibility that its precision could be used by hostile forces as a source of accurate targeting data against

U.S. interests.

When it was enabled, SA reduced GPS’s absolute and repeatable accuracy from a maximum of 30 meters (better than 100 feet) 95 percent of the time, to 100 meters (better than 330 feet) 95 percent of the time. However, this accuracy didn’t meet the U.S. Coast Guard’s requirement of 8-20 meters for navigating in harbors, so the Coast Guard then developed a system of differential corrections—differential GPS or DGPS—to


allow them to effectively circumvent SA’s built-in errors. SA was officially ended in the year 2000, but the advantage of using DGPS over non-SA GPS is still clear and desirable for the safety of marine navigation. That is, mariners who need better than 100 meters will probably also need better than 30 meters.

What is Differential

GPS (DGPS)

The majority of mariners use GPS in conjunction with a chart plotter, but for any given position solution there’s an error budget: dilution of GPS precision, errors in cartography from both government and private sources, datum shifts, latency of displayed position fix and so on, all compound errors in the displayed position. For example, imagine a chart plotter at full-scale zoom showing a channel 200 feet wide (60 meters). A vessel navigating through that channel may well appear to be

“on the rocks” if it’s 30 meters out of place! Although this magnitude of error won’t always be the case, prudent navigators should always choose the maximum margin of safety. Furthermore, the precise location of bottom features for fishing and diving is significantly degraded without some kind of DGPS, and therefore would usually be of little use unless there’s better than the 100 feet of accuracy (30 meters) of non-differential GPS.

The 958 offers two kinds of differential corrections:

•

• WAAS satellite differential

Radiobeacon differential

What is WAAS satellite differential?

One type of differential corrections involves the tracking of

WAAS satellites using Northstar’s 2201, a 12-channel GPS/

WAAS pod. The self-contained 2201 provides the 958 with accuracy of better than 2 meters 2dRMS.

What is radiobeacon satellite differential?

Another type of differential corrections comes from fixed

“reference stations,” and is broadcast by marine radiobeacons over a relatively limited area—usually a maximum broadcast radius of 250 miles—to DGPS receivers. The precise geographic


location of the reference station is used to calculate corrections based on the GPS data received from the satellites.

These corrections are then broadcast to DGPS receivers, which then convert this data into extremely precise position, heading, and speed information. Referred to as “beacons,” the transmitters are situated at various locations along the U.S. coastline and Great Lakes. Most of them are former marine radiobeacon sites.

When using beacon differential through an optional external

Northstar radiobeacon receiver, the 958 provides an accuracy of one to three meters 50 percent of the time, and an accuracy of four meters 95 percent of the time. Lat/lon positions are displayed to thousandths of minutes (approximately six feet).

In addition to accurate positioning information, beacon differential provides critical integrity monitoring of these received GPS signals, enabling a satellite problem to be corrected in seconds, as opposed to hours using uncorrected

GPS. The integrity monitor tells the DGPS receiver to switch automatically to other available satellites.

What is Loran?

Although susceptible to weather, and limited to coastal use, loran is a dependable system familiar to thousands of mariners. Since the 1970’s, loran users have relied on its ability to repeatedly return them to a previously saved location with extreme accuracy. Fishermen have especially appreciated this capability when each subsequent visit to a lobster trap or buoy was virtually “on the mark,” saving them valuable time and money. Loran’s repeatable accuracy was superior to anything else commercially available at the time, and still outperforms non-differential GPS in repeatable accuracy .

In very good coverage areas, loran can typically get you within

50 feet (or approximately 14 meters) of your previously visited target. On the other hand, uncorrected GPS can only be counted on to get you to within about 100 feet (20-30 meters), maximum, of your intended destination. Obviously then, uncorrected GPS wouldn’t be as much help in finding a mark in dense fog. Since most loran chains were configured for optimum coastline navigation, it’s easy to see why loran’s


Page 186 repeatable accuracy has served harbormasters and fishermen so well over the last 25 years.

Loran, however, isn’t as proficient as GPS in absolute accuracy , or when visiting a spot for the first time. Loran transmits at a relatively low frequency (100 kHz—similar to that of an AM radio). Your ability to get an accurate position fix is directly related to the following factors:

•

• your distance and line geometry from the loran transmitters and monitor stations the weather, topography, and ionospheric conditions between you and the transmitters

In these two areas GPS consistently excels when it comes to absolute accuracy. GPS provides an absolute accuracy better than 100 feet nearly everywhere in the world, under virtually any conditions. This far surpasses the 600-foot absolute accuracy that’s achievable from a good loran receiver under ideal conditions.

If you’re used to your Northstar loran’s repeatable accuracy always returning you to within a boat length of a lobster trap or buoy, you won’t necessarily see this same performance with uncorrected GPS. Instead, you could be as far as 200 feet from your expected position. This is especially apparent when you’re displaying the 958’s CHART screen, where you can see your vessel’s plotted position appear to wander around within an area up to 200 feet in diameter (see figure below).


Figure 9: Position accuracy of uncorrected GPS

With good DGPS corrections, your 958 should provide better than four-meter accuracy (repeatable and absolute) 95 percent of the time. SOG readings should be accurate to 0.1 knot.

You can connect your 958 to your loran receiver (as long as the loran has the appropriate NMEA 0183 output capability), and display and navigate with real-time loran TDs. With this configuration, you’ll keep the repeatable accuracy of your loran, but will add all of the navigation features of the 958, including the worldwide absolute accuracy of GPS.

Introducing radar

The name RADAR is derived from the phrase “Radio detection and ranging.”

How does radar work?


Radar is easy to understand if you take this example: Suppose you shout towards a cliff, and in a few seconds you hear the echo. Knowing the speed of sound is constant (approximately

1,100 feet per second), you can therefore start a stop-watch at the time you yell (moment of transmission) and stop the watch when the echo (reflective sound) is heard. Let’s say that time is

6 seconds. You can now calculate your distance from the cliff by multiplying the speed of sound per second, times the number of seconds, divided by 2. (Don’t forget: the total time

Page 187

is for the sound to travel to the cliff and back; you want the distance one way only.)

The calculation is: 1,100 x 6 = 6,600/2 = 3,300 feet.

Radio waves transmitted with high power and very high frequency bounce back from hard objects (called “targets”) exactly the same way your voice is bounced from the cliff. The speed of radio waves is constant (162,000 nautical miles per second), so a computer inside the radar receiver acts as a stop-watch to measure the time. The result is then displayed on a radar screen. The technical name for a radar screen is

Plan Position Indicator (PPI).

How does the radar screen work?

Think of a radar operator as looking down from a helicopter flying above the boat. The helicopter is always above the boat and in the center of the display. The ship’s heading is indicated by the heading marker, an electronic line that extends from the center of the screen to the edge of the display. It points towards the bow of the boat.

Range rings are concentric rings that represent distance from your vessel. They are changed any time the radar range is adjusted; therefore, the operator must be careful to note what range the display is on. An object three rings away on a 0.5 nm per range ring is 1.5 nm from the boat. However, on a 5 nm per range ring, the object is 15 nm from the boat.

Detectability of radar

In standard atmospheric conditions, there are three basic horizons: geometric, optical, and radar. Geometric is the straight line between the sighting point and the horizon. The optical horizon is caused by the normal bending of light waves and this increases the geometric horizon by about 6 percent.

The radar horizon is created by the even greater curvature of radio waves and extends the horizon by about 15 percent.

Radio waves generally travel in straight lines. Hence the detectable range of radar increases in accordance with the height of the radar antenna and the target. For this reason, and when set to a long range, a coast line may not be seen yet the high mountains inland further away may be detected.


Another important factor in the detectability of a radar echo is the strength of the reflected wave. This strength will vary depending on the type of material, size, shape, and height of the target. Among the strong reflectors are bluffs facing the ship, buildings, breakwaters, rock walls, and mountains. Some of the weaker targets are wooden boats, sandy beaches, and rubber lifeboats.



Appendix B - System Features

GPS and WAAS

• self-contained 12-channel L1 GPS/WAAS pod antenna-receiver

• 2-channel WAAS reception

•

•

•

WAAS accuracy < 2 meters 2dRMS accurate, worldwide position data in any weather, 24 hours a day fast signal acquisition

•

• fast-reacting, accurate speed and course accepts SC104 data from optional radiobeacon receiver

Radar

• range of 36 to 72 NM, depending on antenna

• range accuracy better than 8 m or 0.9 percent of maximum range of scale in use

• bearing accuracy better than +1 degree

•

• power requirements, 10.1 to 40.1VDC

connects directly to Northstar 958, with a choice of antennas

General

• Course-up, leg-up, heading-up, and north-up chart viewing angles

• Video in

• VGA out

•

• Fully functional remote control (optional)

Split screen sounder/chart (using optional Northstar 490)

Charting

• Nav-Chart cartridges by Navionics™

• Scales from 8192 nm to 1/4 nm

• Displays chart data, vessel, waypoints, routes, tracks

• Built-in worldwide data to 128 nm and better scales


Position data

• Latitude/longitude (158 datums) from GPS with one-second updates

• Phantom Loran-C TDs calculated from GPS

• Real-time GPS/DGPS status screens

• Loran-C TDs from an external source (two-second update rate)

Steer screens

• Large, graphical presentation

• Cross-track error (traditional and three-dimensional)

• Waypoint name, position

• Bearing and distance to waypoint

• Speed/Course-Over-Ground (SOG and COG)

• Estimated Time of Arrival (ETA)

• Estimated Time Enroute (ETE)

• Automatic magnetic variation

• Course correction

• Speed of Advance

Waypoint and route

Page 192

management

•

•

•

•

•

• Instantaneous panning and zooming

“Find-it-fast” cursor locator pointers

Vessel-centered mode or cursor-following browse mode

Chart redraw in less than ¾ second

“No-Chart” indicator

CHART screen shows the following information:

> your vessel’s position relative to nearby waypoints

> your vessel’s recent track line

> your vessel’s intended course line

> avoidance areas

• Enter waypoints graphically or numerically: as lat/lon, distance and bearing, or loran TDs


•

•

•

•

•

•

•

•

•

•

User-entered avoidance waypoints

Displays up to 30 closest waypoints ( 3D STEER screen)

Store up to 1,000 waypoints and 500 routes

Store 35 waypoints per route

Displays waypoints:

> on the CHART screen

> on an alphabetical list

> on a local list (in order of distance from your present position)

> on a local avoidance list (in order of distance from your present position)

Update waypoint coordinates to vessel’s position

Edit/erase waypoints or routes directly on the CHART screen or on list screens

Plan-route function

Plot any route with automatic chart-scale selection

Plot the position of:

> land masses

> nav aids

> landmarks

> nearby waypoints

> routes

> avoidance areas

Waypoint navigation


•

•

•

•

•

•

• “Point-and-shoot” navigation on the CHART screen

Navigate to coordinates, waypoints, and along routes

Save current position

Steer to new point (go to any waypoint or coordinates at any time)

Waypoint queuing

Follow stored routes forward or backward

Plot current route on chart

Page 193

Nav log

• Arrival time for waypoints passed

• ETA for all waypoints not yet passed in trip

• ETA for total trip

• Reverse the trip

•

•

•

Add waypoints to end of trip

Distance and bearing for all legs

Skip forward and back in trip

Other functions

• Anchor watch

• Avoidance-area alarm

• GPS clock

• TideTrack™ (tide-prediction software integrated with the display at any U.S. and Canadian NOAA tide station for today or any other date up to the year 2010)

Interfacing

• Two bi-directional NMEA I/O ports, 1 auxiliary port

• Two bi-directional RS-232 ports

• Waypoint upload/download capability

• NMEA output sentences: APB, BOD, BWC, GGA, GLC,

GLL, GSA, GSV, LCD, HSC, MSS, RNN, RMA, RMB, VTG,

WCV, XTE, ZDA, ZTG. Conforms to NMEA v 2.0 and later.

Supports 1.5 GLL and BWC.

• One VGA out port (connects to Northstar 1200 Series or other monitor)

• One VIDEO in port (NTSC/PAL) - accepts all standard video sources

• NMEA input sentences: WPL and others

• 200 PPNM speed output

• Honk output

• Accepts most external loran receivers


Physical/ environmental features

•

•

•

•

•

•

•

•

•

•

•

Waterproof control head

10.4” diagonal color LCD display screen

Unsurpassed sunlight viewability

640 x 480 pixel, high- temperature, backlit, transmissive, color LCD

Flush mount standard

High-contrast, anti-reflective screen

Waterproof chart-cartridge door

Large, easy-to-use backlit controls

Easy interfacing I/O connectors

10-36 volts DC power

0 degrees Celsius - 55 degrees Celsius max 95 percent relative humidity, non-condensing



Appendix C - Geodetic Datums

Table 9: Available 958 datums

ID Datum name ELLIPSOID delta x

ADI_MN

ADI_E

ADI_MA

ADI_SE

ADI_SU

AFG

AIN

ADINDAN Mean—Africa CL1880

ADINDAN—Ethiopia CL1880

ADINDAN—Mali CL1880

ADINDAN—Senegal CL1880

ADINDAN—Sudan CL1880

AFGOOYE—Somalia KRASS

AIN EL ABD 1970—Bahrain Island INTL

ANA ANNA 1 ASTRO 1965—Cocos Islands

ARC50_MN ARC 1950 mean value

ARC50_B ARC 1950—Botswana

ARC50_L

ARC50_M

ARC50_S

ARC 1950—Lesotho

ARC 1950—Malawi

ARC 1950—Swaziland

AUSTR

CL1880

CL1880

CL1880

CL1880

CL1880

ARC50_ZR

ARC50_ZM

ARC50_ZB

ARC 1950—Zaire

ARC 1950—Zambia

ARC 1950—Zimbabwe

ARC60_MN ARC-1960 mean value

ARC60_K ARC 1960—Kenya

ARC60_T ARC 1960—Tanzania

ASC

ABE

AB4

Ascension Island 1958

Astro Beacon “E” (Pacific Isl.)

Astro B4 Sorol Atoll (Hawaiian Islands)

CL1880

CL1880

CL1880

CL1880

CL1880

CL1880

INTL

INTL

INTL

-169

-147

-142

-160

-161

-158

-207

145

114

-491

-143

-138

-125

-161

-134

-166

-165

-123

-128

-161

-43

-150 delta z

-278

-283

-293

-300

-300

-299

52

-272

-333

435

-294

-289

-295

-317

-295

204

206

220

224

205

45

-2 delta y

-8

-7

-12

-19

-74

-96

107

75

-116

-22

-90

-105

-108

-73

-105

-15

-11

-20

-18

-14

-163

-251


Table 9: Available 958 datums (continued)

ID Datum name ELLIPSOID delta x

AD714

AS52

AG66

AG84

BEL

BER

BOG

CMI

CA66

CAPE

CC_MN

CARTH

CHAT

Astro Dos 71/4 (Atlantic Isl.)

Astronomic Station 1952

Australian Geodetic 1966

Australian Geodetic 1984

Bellevue (IGN)

Bermuda 1957

Bogota Observatory (Colombia)

Campo Inchauspe

Canton Astro 1966

Cape (South Africa)

INTL

INTL

CL1880

Cape Canaveral mean value CL1866

Carthage CL1880

Chatham 1971 (S.W. Pac. Isl.) INTL

INTL

INTL

AUSTR

AUSTR

INTL

CL1866

INTL

CHUA

CORR

DJAK

Chua-Astro INTL

Corrego-Allegre INTL

Djakarta (Batavia) B1841

DOS68

EI67

DOS 1968 (S.W. Pac. Isl.)

Easter Island 1967

EUR50_MN European 1950—mean value

INTL

INTL

INTL

EUR50_WE

EUR50_CY

EUR50_EG

EUR50_GB

EUR50_GR

EUR50_IR

European 1950—Western Europe

European 1950—Cyprus

European 1950—Egypt

European 1950—England

European 1950—Greece

European 1950—Iran

INTL

INTL

INTL

INTL

INTL

INTL

-134

-206

-377

230

211

-87

-87

-104

-130

-86

-84

-117

-148

298

-136

-2

-263

175

-320

124

-133

-134

-127

-73

307 delta y

229

172

681

-199

147

-98

-96

-101

-117

-96

-95

-132

136

-304

-108

150

6

-38

550

-234

-48

-48

-769

213

304 delta z

-29

-6

-50

-752

111

-121

-120

-140

-151

-120

-130

-164

90

-375

-292

181

431

113

-494

-25

148

149

472

296

-318


KERT

KKJ

LC5A

LIB64

LUZ_P

LUZ_M

MAHE

IND_BIN

IRE65

ISTS

JI61

JAND

KERG

ID

EUR50_SA

EUR50_SI

EUR50_NF

EUR50_PS

EUR79

GAND

GD49

GUAM63

GUX

HJOR

HK

IND_TV


Datum name

European 1950—Sardinia

European 1950—Sicily

European 1950—Norway and Finland

European 1950—Portugal and Spain

European 1979

Gandajika Base (Indian Ocean)

Geodetic Datum 1949

Guam 1963

Gux 1 Astro

Hjorsey 1955—Iceland

Hong Kong 1963

Indian (Thailand/Vietnam)

Indian (Bangladesh/India/Nepal)

Ireland 1965

ISTS 073 Astro 1969

Johnston Island 1961

Kandawala—Sri Lanka

Kerguelen Island (Indian Ocean)

EVRST

AIRYM

INTL

INTL

EVRST

INTL

Kertau 1948 (Malaysia)

KKJ (Finnish)

L.C. 5 Astro (Caribbean)

EVRSTM -11

FINN -78

CL1866 42

Liberia 1964 CL1880

Luzon—Phillipines CL1866

Luzon—Mindanao Island

Mahe 1971 (Indian Ocean)

CL1866

CL1880

-90

-133

-133

41

289

506

208

191

-97

145

ELLIPSOID delta x

INTL

INTL

-97

-97

INTL

INTL

INTL

INTL

INTL

CL1866

INTL

INTL

INTL

EVRST

252

-73

-156

214

-87

-88

-86

-133

84

-100

851

-231

124

40

-77

-79

-220

734

-122

-435

-77

787

-187 delta y

-103

-88

-95

-109

-98

-321

-22

-248

-209

46

-271

836

5

-97

147

88

-51

-72

-134

257

611

-229

-204

86

103 delta z

-120

-135

-120

-122

-119

50

209

259

-751

-86

-189

303



ID Datum name

MASI

MASS

MERCH

MA61

MINA

NAH_O

NAH_UA

Marco Astro—Salvage Islands

Massawa (Africa)

Merchich (Africa)

Midway Astro 1961

Minna (Africa)

Nahrwan—Masirah Island (Oman)

Nahrwan—United Arab Emirates

NAH_SA

NAP

Nahrwan—Saudi Arabia

Naparima BWI (Trinidad and Tobago)

NAD27_MN North American 1927—CONUS mean value

NAD27_WU North American 1927—Western U.S.

NAD27_EU North American 1927—Eastern U.S.

NAD27_AK North American 1927—Alaska

NAD27_BH

NAD27_SS

North American 1927—Bahamas

North American 1927—San Salvador Island

NAD27_CN North American 1927—Canada

NAD27_AB

NAD27_EC

North American 1927—Alberta and B.C.

North American 1927—East Canada

NAD27_MO North American 1927—Manitoba and Ontario

NAD27_NE

NAD27_YK

NAD27_CZ

NAD27_CR

North American 1927—N.W. Terrs. & Sask.

North American 1927—Yukon

North American 1927—Canal Zone

North American 1927—Caribbean

NAD27_CA North American 1927—Central America

NAD27_CU North American 1927—Cuba


CL1866

CL1866

CL1866

CL1866

CL1866

CL1866

CL1866

CL1866

CL1866

CL1866

CL1866

CL1866

CL1880

INTL

CL1866

CL1866

CL1866

CL1866

INTL

B1841

CL1880

INTL

CL1880

CL1880

CL1880

-7

-22

-9

-4

1

-10

0

-7

4

-7

0

-9

-8

-9

-5

-231

-2

-8

-289

639

31

912

-92

-247

-249 delta y

154

140

158

162

160

157

159

139

125

152

125

152

-196

374

160

159

161

135

-124

405

146

-58

-93

-148

-156 delta z

178

165

187

188

190

184

188

181

201

178

194

178

482

172

176

175

179

172

60

60

47

1227

122

369

381



OSGB_E

OSGB_IM

OSGB_SSI

OSGB_WL

PDLN

PA67

PSC63

PSA56_MN

PSA56_BO

PSA56_NC

PSA56_SC

PSA56_CO

PSA56_EC

ID Datum name

NAD27_GR North American 1927—Greenland

NAD27_MX North American 1927—Mexico

NAD83

OB1966

OEG

OHW_MN

OHW_HW

OHW_KA

OHW_MA

OHW_OA

OMAN

OSGB_MN

North American 1983

Observatorio 1966 (Atl. Isl.)

Old Egyptian

Old Hawaiian—mean value

Old Hawaiian—Hawaii

Old Hawaiian—Kauai

Old Hawaiian—Maui

Old Hawaiian—Oahu

ELLIPSOID

CL1866

CL1866

GRS80

INTL

HELM

CL1866

CL1866

CL1866

CL1866

CL1866

Oman CL1880

Ordin. Survey of Gr. Britain 1936—mean value AIRY delta x

11

-12

65

56

-346

375

61

89

45

0

-425

-130

Ordin. Survey of Great Britain 1936 —England

Ord. Surv of G.B. 1936—Scot. & Shetlnd Islands

Pico De Las Nieves—Canary Islands

Pitcairn Astrological—1967

Provisional S. Chilean 1963

Provisional S. American 1956—mean value

Provisional S. American 1956—Bolivia

Provisional S. American 1956—N. Chile

Provisional S. American 1956—S. Chile

Provisional S. American 1956—Columbia

Provisional S. American 1956—Ecuador

AIRY

Ordin. Survey of G. B. 1936—Isle of Man, Wales AIRY

AIRY

Ordinance Survey of Great Britain 1936—Wales AIRY

INTL

INTL

INTL

INTL

INTL

INTL

INTL

INTL

INTL

16

-288

-270

-270

-305

-282

-278

371

371

384

370

-307

185

196

175

188

183

243

169

171

-112

-111

-111

-108

-92

165 delta y

114

130

0

-169

110

-285

-279

-290

-290

-284

-1

-111

93

-376

-388

-390

-442

-371

-367

434

434

425

434

127

42 delta z

195

190

0

81

-13

-181

-183

-172

-190

-181

224

431


ID

SA69_AG

SA69_BO

SA69_BR

SA69_CH

SA69_CO

SA69_EC

SA69_GY

SA69_PA

SA69_PR

SA69_TT

SA69_VZ

SASIA

PSA56_GY

PSA56_PR

PSA56_VN

PRICO

QUAT

QORN

REUN

ROME

SDOS

SBRAZ

SHILL

SCHW

SA69_MN

Page 202


Datum name

Provisional S. American 1956—Guyana

Provisional S. American 1956—Peru

Provisional S. American 1956—Venezuela

Puerto Rico

Qatar National

Qornoq (Greenland)

Reunion (Indian Ocean)

Rome 1940

Santo (DOS) (S.W. Pacific Isl.)

Sao Braz (Atl. Isl.)

Sapper Hill 1943

Schwarzeck (Namibia)

South American 1969—mean value

South American 1969—Argentina

South American 1969—Bolivia

South American 1969—Brazil

South American 1969—Chile

South American 1969—Colombia

South American 1969—Ecuador

South American 1969—Guyana

South American 1969—Paraguay

South American 1969—Peru

South American 1969—Trinidad and Tobago

South American 1969—Venezuela

South Asia


SA1969

SA1969

SA1969

SA1969

SA1969

SA1969

SA1969

SA1969

SA1969

SA1969

-53

-61

-58

-45

SA1969 -45

FS1960M 7

-75

-44

-48

-62

-61

-60

INTL

INTL

INTL

CL1866

INTL

INTL

INTL

INTL

INTL

INTL

INTL

B1841N

SA1969

-225

170

-203

-355

616

-57

-298

-279

-295

11

-128

164

94 delta y

-1

6

3

-1

2

-2

3

2

0

12

8

-10

16

97

1

-65

42

141

159

175

173

72

-283

138

-948 delta z

-44

-36

-44

-37

-48

-41

-47

-33

-44

-33

-33

-26

9

84

53

74

-251

-41

-369

-379

-371

-101

22

-189

-1262


ID

SEBAS

SWBAS

TIMB

TOK_MN

TOK_JP

TOK_KR

TOK_OK

TA68

VL16

WE60

WGS72

WGS84

ZAND


Datum name

Southeast Base

Southwest Base


INTL

INTL

-499

-104

Timbalai 1948 (Malaysia)

Tokyo mean value

EVRST

B1841

Tokyo—Japan B1841

Tokyo—Korea B1841

Tokyo—Okinawa B1841

Tristan Astrological 1968 (S. Atl.) INTL

Viti Levu 1916 (S.W. Pac. Isl.)

Wake-Eniwetok 1960

WGS 1972

WGS 1984

Zanderij (S. America)

CL1880

HOUGH

WGS-72

WGS

INTL

0

0

51

101

-265

-689

-128

-123

-128

-135

-632 delta y

-249

167

691

481

483

481

478

438

0

0

391

52

120 delta z

314

-38

-46

664

662

665

661

-609

-36

-39

4.5

0

-358



Appendix D - Glossary

accuracy absolute accuracy— the accuracy of displayed lat/lon coordinates of your present position as compared to true lat/ lon determined from a chart or other reference source.

repeatable accuracy— the ability to return to the same location using a receiver’s previously-obtained coordinates.

acquisition The procedure—and the time it takes—during which a GPS receiver tries to track satellites, but before it actually computes a position fix.

almanac Data describing the precise orbits of GPS satellites, obtained automatically from satellite signals and stored in a GPS receiver. The first time the receiver is turned on, it requires about 15 minutes to collect almanac data. Thereafter, it usually can use the almanac data previously collected.

Avoidance point A waypoint that you enter into the database and define by its radius and either its lat/lon, or loran TDs, or distance and bearing. It indicates an area into which you specifically want to avoid navigating.

beacon

A radio transmitter, operated by the U.S. Coast Guard, which supplies differential corrections to GPS receivers.

bearing

The magnetic course from your present position to a waypoint.

cartography

The art or technique of making maps or charts.

chain

A group of loran transmitters comprising a master station and at least two secondaries.

COG

C ourse O ver G round. The actual path of your vessel relative to the surface of the earth; that is, the direction your vessel is actually moving.

coordinates

A position defined by either latitude and longitude; TDs; or distance and bearing. The positions of lat/lon and TDs are referred to as absolute, and distance and bearing are relative

(that is, distance and bearing are in relation to a certain reference point).


course-up

An orientation on the chart screen in which the viewing angle matches your true course during the last few seconds, as determined by the GPS receiver.

coverage

The extent to which a geographical area is encompassed by usable GPS or loran signals.

cross-track error

The difference between your desired track and your actual track; that is, how far off you are from your intended course line.

cursor

The display panel indicator that shows which character or character field is ready to be changed, acknowledged, or entered by the user. It’s activated and positioned by the user when required. The 958’s cursor appears as an arrow or a flashing block, depending on whether you’re choosing or entering data. Also known as the red circle on the CHART screen, which you manually activate and position.

DGPS

D ifferential G lobal P ositioning S ystem. A technique developed by the U.S. Coast Guard for correcting basic GPS position to increase its accuracy from 20-30 meters (65-100 feet) to 1-3 meters (3-9 feet).

ephemeris

Data used to calculate exact satellite positions, continually updated and derived from information relayed to the 958 in each satellite’s data stream.

EBL

E lectronic B earing L ines. Markers that you can place on top of the radar image to aid in navigation and in keeping track of your surroundings.

ETA

E stimated T ime of A rrival at the next waypoint, as calculated by the 958 according to your present speed of advance (SOA) and distance to the waypoint.

ETE

E stimated T ime E nroute to the next waypoint, as calculated by the 958 according to your present speed of advance (SOA) and distance to the waypoint.

GPS

G lobal P ositioning S ystem. A navigation system using signals from earth-orbiting satellites. The system is capable of providing high accuracy under all weather conditions.


great circle

Shortest possible path between two points on the surface of a sphere.

GRI

G roup R epetition I nterval. The characteristic identifying period of signals emitted by each loran transmitting chain. The identifier 9960 (Northeast US) indicates that the gap between the start of any two adjacent master signals is 99,600 microseconds long.

HDOP

H orizontal D ilution of P recision.

heading

The compass direction toward which the longitudinal axis of a vessel points.

knot

One nautical mile per hour.

latitude

Imaginary lines on the earth's surface running East/West and expressed in degrees (0-90) north or south of the Equator.

Used with the North/South lines of longitude to determine position.

leg

The line, or path, between any two adjacent waypoints in a route.

leg-up

An orientation of the CHART screen in which the viewing angle matches your desired track when navigating, on a leg-by-leg basis.

longitude

Imaginary lines on the Earth's surface running North/South and expressed in degrees (0-180) east or west of the Prime

Meridian (a line running from the North to South Pole, passing through Greenwich, England).

Loran-C

LO ng RA nge N avigation. A system of land-based radio transmitters emitting precisely timed pulses that are received and translated into position “fixes” by a loran receiver. The 958 can convert and display its GPS coordinates into Loran-C position measurements, or TDs.

loran chain

A group of loran transmitters comprising a master station and at least two secondary stations.

loran receiver

An electronic position finding device that receives pulses from loran stations.

magnetic variation

The difference between magnetic North and true North. Since the difference varies according to geographic location, the


Northstar 958 automatically calculates magnetic variation and uses it to display bearings as magnetic north. The variation at any location changes slowly over a period of years, and the unit compensates, according to the current calendar year.

master

The primary loran transmitter in a “chain” of at least three stations which initiates a series of coded pulses and is followed by the secondaries.

mile (statute)

A unit of measurement (distance) equal to 5,280 feet (1,609.3 meters).

nautical mile (nm)

An international unit equal to 6,076.115 feet (1,852 meters) used officially in the U.S. since 1959. A nautical mile is about

800 feet more than a statute mile.

nav aid

Aids to navigation often used on coastal and inland waters.

Buoys, lighthouses, and daymarkers are nav aids.

NMEA

N ational M arine E lectronics A ssociation. The industry group that establishes the standards for exchanging data between electronic navigation equipment. The standard that’s currently in wide use is NMEA 0183, which specifies the format for sentences containing specific types of data.

Phantom Loran

Northstar’s exclusive loran-simulation feature that mathematically converts GPS lat/lon coordinates to loran

TDs—in real time, as you travel—enabling you to display your current position as TDs.

PPNM

P ulses P er N autical M ile.

radar

Ra dio D etecting A nd R anging.

rhumb line

A constant, true direction to your destination, which appears as a straight line on a Mercator grid. Compare with great circle .

route

A group of two or more pre-defined waypoints that form a connected path to and/or from specific locations. In its simplest form, a route can be a straight line to a single waypoint.

satellite

An object orbiting the earth. GPS satellites are controlled by ground stations, and transmit signals that can be used to calculate position and speed. WAAS satellites.


secondaries

The “slave” loran transmitters in a chain of at least three stations.

SNR

S ignal-toN oise R atio. Guide number for determining the relative quality of GPS, DGPS, or loran signals as compared to background radio “noise.”

SOG

S peed O ver G round. The actual speed of your vessel relative to the sea bottom.

TD

Time Difference. The measured amount of time—in millionths of a second—between loran signals received from the master and the secondary stations.

target

Boats or ships, navigational markers, land masses, or any other object detected by radar.

track

A desired line of travel, or path already travelled.

VRM

V ariable R ange M arker. A circle on the radar, surrounding one of the end points of the electronic bearing line, used to measure distances from that end point to any other point of interest on the screen.

WAAS

W ide A rea A ugmentation S ystem.

waypoint

A particular location (defined for navigation purposes by its lat/lon, distance and bearing, or TDs), used as an intermediate or final destination.



Index

A

Accuracy absolute 186 comparing loran to GPS in 186 definition of 183, 205 with DGPS 187 with GPS 187 of the DGPS receiver 63, 185 of the GPS receiver 63 repeatable definition of 183, 205 with DGPS 187 with GPS 186 with loran 185, 187 with Phantom Loran 69

Aids to navigation. See Navigation

Alarms anchor 153 arrive radius 154 audible 82, 155–157 avoidance area 82 cautions 81 clearing 9, 23, 145 cross-track 154

DGPS 155 honk. See Alarms, audible icons 23, 144, 146–152 messages 145 setting 152 understanding 31, 144–157

Arrive radius. See Alarms

Avoidance area creating on the chart screen 80


definition of 80 removing from waypoint 84 setting alarm to beep 82

B

Beacon receiver. See DGPS receiver

Beacon, baud rate 64, 175

BRIGHTNESS key 36

Brightness. See display screen 21

Browse mode changing to vessel mode 46 definition of 45

C

Cartography, definition of 205

Chart cartridge access door bypassing safety features 181 cautions 181 inserting properly 10 maintenance 26 obtaining 10

CHART function key 30

Chart screen changing chart display details 54–55 chart scale 41 choosing tide stations from 158 controlling 48–49, 133 creating routes on 95 creating waypoints on 74 displaying with Navionics Nav-Chart cartridges 7 displaying your present position on 7 editing a route from 100 menu keys 10 plotter function 22, 42 radar and. See Radar rotating 49–52


Charts, electronic cautions 38 chart boundary lines 38 displaying outlines of 55 understanding 38

CLEAR key 35

Clearing alarms. See Alarms 23

COG. See Course-over-ground.

Connecting the 958. See Interfacing 72

Contacting Northstar 3

Controls (keys), introducing the functions of 20

Course-over-ground displaying on chart screen 13, 134 displaying on radar 134 displaying on steering screens 113

Cross-track alarm 154 displaying 114–116 error, zeroing out 118

Cursor definition of 206 finding on the chart screen 32 symbol on chart screen 42 using on the chart screen 42–43

Cursor pad pressing to control cursor 32, 42 using the 32

D

Database sharing (waypoints/routes). See importing and exporting waypoints and routes

Date. See Time and date

Datum changing 170 definition of 170 displaying geodetic 61 list of available 197


Demo mode, using 14

DGPS accuracy 187 choosing as nav source 168 corrections differential 174, 183, 187 handling interruptions in 176 indicator on screen 64 receiver accuracy of 174 automatic control of 174 changing the settings 173 displaying position information from 63–65 manual control of, choosing 175 self-test results 179 status of 64, 70 understanding differential 184

Differential GPS. See DGPS

Display screen adjusting the brightness 22, 36 dimming (auto) 22 splitting 46–48

Distance and bearing calculating 165 displaying 39, 64, 74, 113, 134 entering on quick waypoint screen 111 understanding 57–58

E

Echo sounder. See Sounder

Electronic bearing lines (EBL) 137–139

ENTER key 35

Entering data using the keypad 34

Ephemeris, definition of 206

ETA definition of 206


displaying on radar 138

ETE displaying on steering screens 115 definition of 206 displaying on radar 138 displaying on steering screens 115

Exporting all waypoints and routes from a unit 85

F

Factory defaults 154, 166, 169, 175, 176

Feedback, sending yours to Northstar 4

Fishfinder. See Sounder

Function keys, using 30–35

G

Global Positioning System. See GPS

GPS absolute accuracy 183 accuracy 63, 174 checking status 62, 67, 70 choosing as navigation source 168 comparing to loran 186 converting coordinates to Loran TDs 68 to Phantom Loran 168 definition of 183, 206 receiver collecting almanac data 205 displaying information from 60–63 software version 180 satellite accuracy of readings from, improving 173 improving accuracy of readings from 61 status of 62

Great circle definition of 207 method of calculating distance and bearing 165


Group Repetition Interval (GRI) definition of 207 setting for loran 67, 77, 79, 111 for Phantom Loran 70

Guard zone 140–141

H

Heading displaying on radar 134

Honking alarms. See Alarms, audible

Horizontal Dilution of Precision (HDOP), definition of 63

I

Icons, alarm. See Alarms

Identification numbers

958 serial number 178 owner’s ID message 166

Import/export between two 958’s 85

Importing all waypoints and routes to a unit 85

IN key 36

Info bar 85, 102 displaying on chart screen 13 displaying on radar screen 133

Interfacing your 958 to a personal computer 91 to other compatible devices 177

K

Keypad testing 180 using the 34–35

L

Lat/lon. See Latitude, Longitude

Latitude definition of 207 displaying 61, 67, 70, 74 entering when creating waypoints 111


setting precision of display 166

Leg (route), definition of 94, 207

Lists displaying waypoints on 72–74 routes displaying on 106 editing on 106 waypoints displaying different coordinates 74 displaying on 72 editing on 83 entering on 78 updating coordinates on 85

Long Range Navigation System. See Loran

Longitude definition of 207 displaying 67, 70, 166 entering 111

Loran choosing as navigation source 168 definition of 207 displaying position as 66 entering TDs on chart screen 77, 79 on quick waypoint screen 111 receiver, displaying data from 66–68

M

Magnetic variation changing 169 definition of 169, 207

Maintaining the 958 cleaning 27 protecting 26

Man overboard mode. See MOB key

Menu keys, overview of 35


Messages alarm 23, 145

GPS status 61 information 23 loran warnings 68 owner identification 166 question 23, 24

MOB key 33

N

Nav log 122–124

NAV LOG function key 32

Navigation aids 39–40, 55 cautions 38, 39, 81, 165, 178, 181 going to a waypoint on the steering screens 112–116 options 167–172 restarting 124 reversing your trip 123 stopping 124

NMEA 0183 177, 187

Noise levels (atmospheric) 65

Northstar, contacting 3

O

OUT key 36

Overlay. See Radar, and Video display image

P

Personal computer, interfacing to 72

Phantom Loran 168 definition of 69 displaying 168

Position converting coordinates 85 converting coordinates from GPS to TDs 68 displaying 7, 60–70, 168 increasing accuracy of 174


PWR key 30

R

Radar adjust radar keys 133, 134–137 alarms 144, 152 choosing the split 132 controlling 133 definition of 126 displaying with SPLIT key 46–48, 126–127 electronic bearing lines (EBL) 137–139 guard zone 140–141 installing and setting up 25 introducing 25 main keys 132–134 overlaying on chart 128–131 radar markers keys 133, 137–141 range rings 141 rotating 53, 131, 133 tuning 137 turning on/off 128 variable range marker (VRM) 138–139

Range rings 141

Returning the 958 for service 4

Rhumb line, definition of 165

RMA number. See Service

Rotating chart/radar 49–52, 131

Routes adding waypoints to beginning of routes 102 to end of routes 104 to middle of routes 103 backing up 4 creating on chart screen 95–97 creating on routes screen 97 definition of 94


editing from chart screen 100–105 using a waypoints list 106–108 while navigating 108 erasing entire 108 importing and exporting between two 958’s 85 navigating from stored 116 removing waypoints from 105, 108 reversing 117 saving as you travel 97–99 starting 117–118 stop saving 99

S

Satellite changing elevation setting 176 effect of DPGS on 185

GPS system 60, 62, 183, 185, 205 status messages 62 status on first start-up 9

SAVE key 33, 97, 180

Serial number required for repair 4 viewing your 958’s 179

Service obtaining technical support 3 returning the 958 for repair 4–5

RMA number 4 warranty statement 4

Setting up your 958 164–177

Sharing waypoints and routes. See Import/export 85

Signal to Noise Ratio definition of 209 using the 64

SNR. See Signal-to-Noise Ratio

SOG. See Speed-over-ground.


Sounder alarms 151 displaying with SPLIT key 46–48 installing and setting up 177 introducing 25 using 25, 177

Speed averaging 61, 173

Speed-over-ground 173 displaying on chart screen 13, 134 displaying on radar 134 displaying on steering screens 113

Split choosing 46–48, 132 introducing 21

STAR function key 23, 31

Startup 5–7

STEER function key 30

Steering screens adding extra accuracy to 171 overview 31 units of measurement for 165 using the 112–116

Support. See Service

Symbols alarm 8 arrow for legs 124 arrow for tide level 158 arrow for waypoint pass status 123 arrows for routes 101, 117, 118 arrows for SOG and COG 113 buoys 39 cursor 32, 34, 42, 206 diamond shaped box 42 dotted line 102, 103 hourglass 21


landmarks 40 miscellaneous for waypoint 75 series of dots (track line) 56 slashed circle 80–81 star 156 vessel 7

T

Target, definition of 126

TDs. See Time differences

Technical support. See Service

TideTrack choosing a tide station 159–160 displaying information for today’s date 160 displaying tide information 158 introducing 26 understanding 158

Time and date actual time of arrival 123 changing time zone 182 displaying 31, 166, 182

Estimated Time of Arrival 122

Time differences (TDs) converting 68, 168 definition of 209 displaying 67–70, 111 entering 77, 79

Track clearing track history 57 definition of 209 definition of track line 55 displaying track history 56 relative to cross-track distance 171

Transmitters 126, 136 transmitters 205

Turning off the 958 7


Turning on the 958 5

V

Variable range marker 138–139

Vessel mode changing to browse mode 44 understanding 44

Video image display displaying with SPLIT key 46–48 introducing 26 using 160–162

VRM. See Variable range marker

W

WAAS, using as a position source 60

Warning radius 81–82, 83

Warranty statement 3, 4

Waypoints adding to routes, and removing 100–108 trip 123 arrive radius 154 assigning symbols to 75 backing up 4 creating routes from 95–97 creating with SAVE key 33 definition of 72, 209 designating as avoidance areas 80–82 displaying 55, 193 displaying coordinates of 74 editing 83–84 importing and exporting between two 958’s 85 listing 72 making a new waypoint on the chart screen 76–78 on the waypoints screen 78–80 naming 83, 96, 99


navigating to quick 16 navigating to stored 112 steering to 112–116 storing 75 transferring to a personal computer 91 warning radius for avoidance areas 81, 83

WAYPTS/ROUTES function key 31

Z

Zooming chart screen 41–42 radar 131


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