AbstractsPhysics

Theoretical considerations indicate that frequency modulation of a weather radar allows a more rapid determination of the long term average echo intensity from several instantaneous echoes. The modulation should be sawtooth in waveform, of period 100c/s and amplitude 10Mc/s for an AN/TPS 10 radar. Use of a rotating vane in the waveguide gave a sinusoidal modulation of period 100c/s and amplitude 8 to 10Mc/s. The local oscillator was kept in step with the magnetron by a sawtooth modulation. The use ot the microwave gyrator as an improvement on the rotating vane is suggested.