§  25.205   Minimum antenna elevation angle.

   (a) Earth station antennas must not transmit at elevation angles less
   than five degrees, measured from the horizontal plane to the direction
   of maximum radiation, in a frequency band shared with terrestrial radio
   services or in a frequency band with an allocation to space services
   operating in both the Earth-to-space and space-to-Earth directions. In
   other bands, earth station antennas must not transmit at elevation
   angles less than three degrees. In some instances, it may be necessary
   to specify greater minimum elevation angles because of interference
   considerations.

   (b) ESAAs in aircraft on the ground must not transmit at elevation
   angles less than three degrees. There is no minimum angle of antenna
   elevation for ESAAs while airborne.

   [ 81 FR 55336 , Aug. 18, 2016]