Radar Operating Distance (Gtn 7Xx Only); Maximum Permissible Exposure Level (Mpel) (Gwx 68); Maximum Permissible Exposure Level (Mpel) (Other Radars) - Garmin GTN 650 Series Pilot's Manual Upgrade Supplement

A smaller incident angle gives the radar a larger detectable range of operation
and the target display will show a higher intensity. Since more radar energy is
reflected back to the antenna with a low incident angle, the resulting detectable
range is increased for mountainous terrain.
5.2

Radar Operating Distance (GTN 7XX Only)

The following information establishes a minimum safe distance from the
antenna for personnel near an operating airborne weather radar. The minimum
safe distance is based upon the FCC' s exposure limit at 9.3 to 9.5 GHz for general
population/uncontrolled environments which is 1 mW/cm
Circular 20-68B for more information on safe distance determination.
5.2.1 Maximum Permissible Exposure Level (MPEL)
(GWX 68)
The zone in which the radiation level exceeds the US Government standard
of 1 mW/cm 2 , is the semicircular area of at least 11 feet from the 12 inch antenna
as indicated in the illustration below. All personnel must remain outside of this
zone. With a scanning or rotating beam, the averaged power density at the MPEL
boundary is significantly reduced.
5.2.2 Maximum Permissible Exposure Level (MPEL)
(Other Radars)
See the appropriate documentation for MPEL.
GTN 650/750 Series SW V3.00 Upgrade Supplement 190- 01007-05 Rev A
Figure 5-4 Angle of Incidence
. See Advisory
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