Garmin Flight Deck 100 Manuel D’Utilisation

190-00728-04  Rev. A

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The angle at which the radar beam strikes the target is called the Angle of Incidence. The figure illustrates

the incident angle (‘A’). This directly affects the detectable range, the area of illumination, and the intensity
of the displayed target returns. A large incident angle gives the radar system a smaller detectable range and
lower display intensity due to minimized reflection of the radar energy.

A smaller incident angle gives the radar a larger detectable range of operation and the target display shows

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.

The  following  information  establishes  a  minimum  safe  distance  from  the  antenna  for  personnel  near

operating weather radar. The minimum safe distance is based on the FCC’s exposure limit at 9.3 to 9.5 GHz for
general population/uncontrolled environments, which is 1 mW/cm2. See Advisory Circular 20-68B for more
information on safe distance determination.

The zone in which the radiation level exceeds the US Government standard of 1 mW/cm2 is the semicircular

area of at least 11 feet from the 12-inch antenna. 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.