Gain Control (Gain) - Honeywell IntuVue RDR-4000 Pilot's Manual

IntuVue RDR-4000 Weather Radar Pilot's Guide

GAIN CONTROL (GAIN)

GAIN control is active in all modes. The
calibrated (AUTO) position is the only
position where the colors represent the
FAA defined reflectivity and rainfall rates
as shown in the table below. The AUTO gain setting provides a
standard reference which all radar manufacturers must follow.
Immediately after turning the GAIN control in either direction out of the
detent position (AUTO), the "MAN GAIN" annunciation appears on the
display indicating that the system is no longer in the calibrated mode.
Rotating the GAIN control counterclockwise decreases gain. Rotating
the GAIN control clockwise increases gain. The gain setting has no
effect on turbulence detection or display. After using gain to assess the
weather, the GAIN knob should be returned to the AUTO position.
Color Returns
Very light or
Black
none
Green Light
Yellow Medium
Red Strong
Magenta Turbulence
Rotating the GAIN Knob to the minimum (MIN) position reduces gain by
approximately 16 dBZ. Rotating the GAIN Knob to the maximum (MAX)
position increases gain by approximately 10 dBZ.
Proper use of the gain control can aid in the detection and assessment
of storm cells. Gain reduction can be useful in several ways. Reducing
the gain to MIN provides a quick assessment of the relative intensity
between displayed cells. Since gain does not affect turbulence
detection, reducing gain in the AUTO mode to MIN will show turbulence
information along with the strongest cells. This is important since the
presence of turbulence along with high levels of reflectivity often
indicates convective weather. In areas of heavy stratus rain, the display
can show large areas of strong returns, but with little associated
turbulence.
D201002000008
Rev 1, December 2014
Reflectivity Color Codes (Gain at AUTO)
Reflectivity
Less than
20 dBZ
20 – 30 dBZ
30 – 40 dBZ
40 dBZ or
greater
N/A
Rainfall Rate
Less than 0.7 mm/hr
(0.028 in/hr)
0.7 – 4 mm/hr
(0.028 – 0.16 in/hr)
4 – 12 mm/hr
(0.16 – 0.47 in/hr)
Greater than 12
mm/hr (0.47 in/hr)
N/A
Expanded Operating Instructions
25