NorthStar 972 Quickstart Manual And Reference Manual page 99

Electronic Bearing Line (EBL)
The Electronic Bearing Line is a marker
that you can place on top of the radar
image to aid in navigation and to keep
track of your surroundings.
Use the cursor pad to move the EBL
around your position to measure the
bearing to any object on the screen.
Variable Range Marker (VRM)
The Variable Range Marker is displayed as
a circle around your vessel. Use the cursor
pad to make the circle bigger or smaller.
The distance to the marker is displayed in
the lower left corner of the screen.
Guard zone
Press the Guard Zone menu key to control
this feature. Echoes detected inside the
guard zone will cause an alarm.
The guard zone is bounded by red lines —
an inner and an outer arc centered on the
vessel, and two straight lines extending
outward from the vessel. The interior of
the guard zone is yellow.
You can turn visibility of the zone on or
off, and change its boundaries.
Reference Manual Revision B
Guard Zone
Figure 4: Guard zone
Press the following keys to adjust each
guard zone.
Press Visibility to show or hide the guard
zone. When the zone is hidden, it doesn't
alarm.
To adjust the position of the guard zone,
press GuardZone (if necessary) so that it
displays . Use the cursor pad to set
Position
the position.
To adjust the size of the guard zone, press
GuardZone (if necessary) so that it displays
. Use the cursor pad to set its size.
Size
Reference section 6 — Radar
Using the Markers keys
95