Airborne Color Weather Radar; Basic Antenna Tilt And Range Setup - Garmin G1000 NXI Cockpit Reference Manual

Hazard avoidance

aIRBoRNE CoLoR WEaTHER RadaR

BaSIC aNTENNa TILT aNd RaNGE SETUP

Proper antenna tilt management techniques are a major factor for the successful use of
any airborne weather system. If the antenna tilt angle is set too low, the radar display will
show excessive ground returns, making it difficult for the pilot to distinguish adverse weather
phenomena from ground clutter. If the antenna tilt angle is set too high, the radar beam will
overscan the top of the adverse weather. In either of these examples, the flight crew would be
unable to adequately recognize critical weather information.
The following discussion is a simple method for setting up the weather radar antenna tilt
for most situations. It is not to be considered an all encompassing setup that works in all situ-
ations, but this method does provide good overall parameters for the monitoring of intense
weather threats. Correct application of tilt angle is directly dependent on the storms height
and intensity and its relative distance from own ship. Adjusting the airborne weather radar
tilt angle setting until minimal ground clutter is displayed is the simplest setup method for
general surveillance of precipitation returns. For ranges of up to 80 NM this ground clutter
should appear on the outer portion of the radar display. At ranges greater than 80 NM, the
displayed ground clutter will move lower on the radar display due to the curvature of the
earth. By displaying a minimal amount of ground clutter on the installed weather radar system
the flight crew can ensure the system is operating and the air mass above the ground clutter
is being scanned.
When a strong a weather return is detected within the ground clutter it must be further in-
vestigated to determine the source of this return. Further tilt angle adjustment of the airborne
radar may be required to explore this return. Adjusting the radar tilt angle upwards can reveal
the radar tops of this return, while adjusting the tilt angle downwards may be necessary to
investigate the strongest intensity of a particular return.
Effective airborne weather radar range management during all phases of flight should be
based on the volume of air to be scanned for returns ahead of own aircraft, to allow sufficient
time needed to investigate, analyze, decide, and tactically maneuver around these hazardous
weather returns. Longer ranges may be used to tactically identify intense weather returns that
may warrant further investigation, and closer ranges may be used during the investigation
process.
There is no one tilt or range setting that works for all situations. It is best to remember that
active tilt and range management is necessary to identify and then investigate returns.
NoTE: When a strong weather return is displayed on the weather radar, the tilt angle
may be adjusted to explore return intensities at various altitudes to aid in determina-
tion of radar tops.
Garmin G1000 NXi Cockpit Reference Guide for the da62
86 190-02622-00 Rev. A