BendixKing IN-182A System RDR-2000 - Manual (Page 36)

SHADOWED AREAS
Extremely heavy rainfall can reduce the ability of the radar energy to
penetrate a weather cell and present a complete picture of the weather
area. This condition is referred to as “radar attenuation”. Under these
conditions ground returns can be helpful in analyzing the weather situa-
tion. Tilt the antenna down and observe the ground returns around the
displayed cell. If no ground returns are displayed on the far side of the
displayed cell (shadowed area), heavy rain may be blocking the radar
energy. This could mean that a larger area of precipitation exists than
that which is displayed.
WARNING: AVOID AND NEVER PENETRATE A SHADOWED AREA.
TARGET RESOLUTION
The ability of a weather avoidance radar system to resolve and display
two or more closely spaced targets is limited in range by the transmitted
pulse width and display range and in azimuth by the antenna beam
width.
RANGE RESOLUTION
The transmitter pulse width in the RDR 2000 is 4 micro-seconds, yielding
a receiver range resolution of approximately 1/3 nautical mile.
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Effective Date: 5/98 RDR 2000 Pilot's Guide: Rev 3
Operation In-Flight