beautypg.com

Navigation data – NorthStar Navigation Multi-Function Unit M84 User Manual

Page 111

background image

Northstar M121/M84 Installation and Operation Manual

110

Navigation data

BRG

Bearing to Destination: Bearing to the destination from the boat.

BRG Bearing to cursor: Bearing to cursor from boat (cursor mode, see section 3-2-1)

CDI

Course Deviation Indicator: When the boat is navigating to a point, the chart and highway windows
show a parallel line on either side of the plotted course. These two lines are called the Course Deviation
Indicator (CDI) lines. The distance from the plotted course to a CDI line is the CDI scale.

Set the CDI scale (see section 17-2) to the maximum distance that the boat should deviate from the
plotted course. The chart and highway windows show the CDI lines, which are like a highway over the
water where the boat will move. The windows show how far the boat has deviated from the plotted
course and if the boat is approaching a CDI line. If the XTE alarm is enabled (see section 17-8) an alarm
will sound if the boat reaches a CDI line.

COG

Course Over Ground: Direction in which the boat is moving over the ground.

CTS

Course To Steer: Optimum course to steer to return to the plotted course.

DTG

Distance To Go: Distance from the boat to the destination.

ETA

Expected Time of Arrival: At the destination, assuming that SOG and COG remain constant.

DST Distance from boat to cursor (cursor mode, see section 3-2)

SOG

Speed Over Ground: Current boat speed over the ground. This is not necessarily the same as the boat
speed through the water nor the speed at which it is approaching the destination.

STR

Steering: The diff erence between COG and CTS.

TTG

Time To Go: The estimated time to reach the destination.

XTE

Cross Track Error: The distance from the boat to the nearest point of the plotted course. XTE may have
a letter: R means steer to the right to return to the plotted course, L means steer to the left.

VMG

Velocity Made Good: The speed at which the boat is approaching the destination.

CTS

SOG (speed)

VMG (speed)

BRG

COG

Destination

Boat position

Start

STR

DTG (distance)

CDI scale
(distance)

Plotted
course

Start

Destination

XTE
(distance)

Boat
position

CDI scale
(distance)

CD

I line

Plotted
course

CD

I l

in

e

This manual is related to the following products: