Honeywell Primus 880 Pilot's Manual page 40

When GMAP is selected, a green GMAP legend is displayed and the
color scheme is changed to cyan, yellow, magenta. Cyan
represents the least reflective return, yellow is a moderate return,
and magenta is a strong return.
If GMAP is selected before the initial RTA warmup period is
complete, a flashing WAIT legend is displayed. In WAIT mode, the
transmitter and antenna scan are inhibited and the memory is
erased. When the warmup is complete, the system automatically
switches to the GMAP mode.
THE SYSTEM PERFORMS ONLY THE FUNCTIONS OF WEATHER
DETECTION OR GROUND MAPPING. IT CANNOT BE RELIED
UPON FOR PROXIMITY
PROTECTION.
FSBY - Forced standby is an automatic, nonselectable radar
D
mode. As an installation option, the controllers can be wired to the
WOW squat switch. When wired, the RTA is in the forced standby
mode when the aircraft is on the ground. In the forced standby
mode, the transmitter and antenna scan are both inhibited, the
memory is erased, and the amber FSBY legend is displayed in the
mode field. When in the forced standby mode, pushing the STAB
button 4 times in 3 seconds, exits the mode.
FSBY mode is a safety feature that inhibits the transmitter on the
ground to eliminate the X- band microwave radiation hazard. Refer
to Section 6, Maximum Permissible Exposure Level (MPEL).
NOTE: In dual installations, overriding the forced standby using
the TGT button is done on only one controller.
FORCED STANDBY MODE MUST BE VERIFIED BY THE OPERATOR
TO ENSURE SAFETY FOR GROUND PERSONNEL.
10 GAIN
The GAIN is a single- turn rotary control and push/pull switch that is
used to control the receiver gain. When the GAIN switch is pushed, the
system enters the preset, calibrated gain mode. Calibrated gain is the
normal mode and is used for weather avoidance. In calibrated gain, the
rotary portion of the GAIN control does nothing.
When the GAIN switch is pulled out, the system enters the variable gain
mode. Variable gain is useful for additional weather analysis and for
ground mapping. In WX mode, variable gain can increase receiver
sensitivity over the calibrated level to show weak targets or it can be
reduced below the calibrated level to eliminate weak returns.
A28- 1146- 102- 00
PRIMUSr 880 Digital Weather Radar System
WARNING
WARNING
WARNING
OR ANTICOLLISION
Operating Controls
3-25