The angle within which an antenna receives radio waves.
The width of the main beam lobe, in degrees, of the transducer. It is usually defined as the width between the "half power point" or "-3dB" point.
The angular width of the radar beam. Usually that width where the power density is one-half that on the axis of the beam ("half-power" or "3 dB" point).
The amount of angle (either azimuth or zenith) covered by the antennas maximum gain (in decibels) until the signal drops of 3dB in each direction.
the angle between the center of the radar beam and the point in the beam where the power of the transmitted energy is one-half of the power at the center's maximum. A WSR-88D radar's beam width is approximately 1 degree.
In SLAR usage this is the angle subtended in the horizontal plane by the radar beam.