2. RADAR OPERATION
2-22
2.22 Guard Alarm
The guard alarm allows the operator to set the desired range and bearing for a guard zone.
When ships, islands, landmasses, etc. violate the guard zone, an audio alarm sounds and
the offending target blinks to call the operator’s attention.
CAUTION
• The alarm should not be relied upon as
the sole means for detecting possible
collision situations.
• A/C SEA, A/C RAIN and GAIN controls
should be properly adjusted to be sure
the alarm system does not overlook
target echoes.
2.22.1 Setting a guard alarm zone
To set a guard alarm zone, set the radar to transmit and do the following:
1. Press the ALARM key.
2. Use the Trackball to set the cursor on the top left corner (or top right corner) of the
guard zone you want to set, then press the SET GUARD1 or SET GUARD2 soft key,
depending on which guard zone you want to set.
3. Use the Trackball to set the cursor on the bottom right corner (or top left corner) of the
guard zone area, then push the ENTER knob.
4. Press the RETURN soft key to finish.
(1) Drag cursor to top (or bottom) corner
for guard zone and press the SET
GUARD1 or SET GUARD2 soft key.
(2) Drag cursor diagonally to bottom (or top)
corner for guard zone and press the [ENTER]
knob.
12/
H-UP
3nm
LP
319. 9
°M
317.2 ˚R
11.60
nm
+
SET
GUARD1
RETURN
12/
H-UP
3nm
LP
39.9 ˚R
8.800
nm
+
NO ALARM
ERASE
GUARD1
SET
GUARD2
SET
GUARD1
RETURN
ALARM
ALARM
GUARD 1
319. 9
°M
1
MOVE +CURSOR TO
ANOTHER CORNER OF
GUARD1 AND PUSH
KNOB TO SET.
SET
GUARD2
2
How to set a guard alarm zone
The equipment then searches for targets inside the guard zone to determine guard alarm
type. If a target is found inside the guard zone, the guard zone type becomes an “Outward
guard alarm,” and any target exiting the guard zone will trigger the audio alarm. If no target
is found, the guard zone type becomes an “Inward guard alarm,” and any targets entering
the guard zone will trigger the audio alarm. The guard alarm type is shown as G1(G2) IN or
G1(G2) OUT.