NorthStar Navigation Multi-Function Unit M84 - Manual (Page 67)

Northstar M121/M84 Installation and Operation Manual 66
18-9 Using the VRM/EBL
Use one, or both of the VRM/EBL (Variable
Range Markers/Electronic Bearing Lines) to
quickly find the precise range and bearing of a
target.
A VRM can be fixed or floating. Use the VRM to
find the range (distance) to the target.
• A fixed VRM is shown as a thin, dashed, circle
centred around your boat. Use this to find
the distance of a target from your boat.
• You can move the centre of the VRM away
from your boat; for example, to measure the
distance between two islands. This is called
a floating VRM.
The EBL is shown as a thin, dashed line
extending from the centre of the VRM to the
edge of the radar window. Use the EBL to find
the bearing of the target.
1 From the radar window, press
MENU
then
select VRM/EBL.
If you turn the target trails on, each target
leaves a 30 second trail on the radar screen. You
cannot change the length of the target trail.
If you turn the target trails off, the targets do
not leave trails.
Note that if the radar motion mode is set to
true, stationary targets won’t leave a trail.
If the radar motion mode is relative, any target
that is moving relative to your boat will leave a
trail.
18-8 Turning the target trails on or off
To change the target trails setting:
1 From the radar window, press
MENU
then
select Presentation .
2 Set the Target trails option to
(target trails are on) or (target trails are
off).
18-9-1 Finding range and bearing with a fixed
VRM/EBL
1 From the radar window, press
MENU
then
select VRM/EBL .
2 Select VRM/EBL then 1 (VRM/EBL 1) or 2
(VRM/EBL 2).
3 Set Enable to to show the VRM and EBL on
the radar window (or to hide them).
4 Select EBL reference if you want to change
the EBL bearing reference. There are two
choices:
• °R shows the EBL bearing relative to your
boat’s head.
• °M/°T shows the EBL bearing relative to
magnetic North or true North.
5 Select Adjust to change the positions of
the VRM and the EBL so that you can align
them with the target. Use:
• and to decrease and increase the
radius of the VRM until it touches the
target to measure the range.
• and to move the EBL until it touches
the target to measure the bearing.
6 The range and bearing of the target is
shown at the bottom of the screen.
7 If you want to hide (or change the
settings for) the range rings, North line,
and/or heading line, press
MENU
then select
Radar .