sensor system). By depressing the switches, ranges of 5,
10, 25, 50, 100, 200, and 300 nautical miles with
corresponding range marks may be selected. Ranges of
600 and 1200 nautical miles are available if the radar
system mode selector switch is in the FP position.
technique pushbutton selector switch. The rain echo
attenuation compensation technique (REACT) pushbutton
selector switch, placarded RCT, is used to enable or
disable the REACT function of the radar system. When
the RCT mode has been activated, receiver gain is
automatically adjusted according to received signal
strength. When receiver is in calibrated range, displayed
colors are as in weather mode. When calibration range is
exceeded, background will be in blue for the affected
areas. Signals in the uncalibrated range will be displayed
as a level three (red). REACT mode may be activated in
all radar ranges. When activated, RCT will be
annunciated on the EHSI.
Attitude stabilization pushbutton selector
pushbutton selector switch, placarded STAB is used to
enable or disable attitude stabilization of the radar image.
When stabilization is selected off, an OFF annunciator
above the STAB switch will illuminate.
Target alert pushbutton selector switch.
The alternate-action, target alert pushbutton selector
switch, placarded TGT is used to enable or disable the
radar target alert feature. When the target alert function
has been selected, TGT (green) will be annunciated on
the EHSI. When the target alert feature has been
selected, the area beyond the selected range and 7.5
degrees on either side of aircraft heading is monitored for
radar returns of level 3 (red) or greater. If a level 3 or
greater return is detected and triggers the system, TGT
will be annunciated in amber on the EHSI. Target alert is
selectable in all but the 300 nautical-mile range.
Sector scan angle pushbutton selector
pushbutton selector switch is used to select either the
normal 14 looks per minute 120-degree scan or the faster
update 28 looks per minute 60-degree sector scan.
Antenna tilt angle control. The rotary
antenna tilt angle control, placarded TILT, is used to
select the angle of the antenna beam with relation to
earth plane. Clockwise rotation tilts the beam upward
from 0 to 15 degrees. Counterclockwise rotation tilts the
beam downward from 0 to 15 degrees. The scale range
between +5 degrees and -5 degrees is expanded for ease
Lightning sensor system mode selector
OFF. Disables lightning sensor
STBY. In the standby (STBY) mode,
lightning data is not displayed. However, the receiving
and processing equipment is active and lightning strikes
are being counted and accumulated.
LX. The LX mode is the normal
working mode of the lightning sensor system. Lightning
Table 3-12. Video Integrated Processor VS Aircraft Radar Return Levels
Video Integrated Processor