Pulse Compression Radar Study.

Pulse compression provides increased detectability by increasing the average transmitted power. This is done by increasing the transmitted pulsewidth instead of the peak power. The technique provides economic advantages by reducing the peak-to-average power ratio. Radar resolution is maintained by compressing the transmitted pulse into a much narrower pulse of nearly arbitrary width. This compression effect is achieved by sweeping the transmit frequency, either linearly or nonlinearly. A nonlinear FM waveform offers a higher signal-to-noise ratio and a narrower occupied bandwidth than linear FM, and would be the logical choice for air traffic control radars. The pulse waveform should be chosen to operate the klystron at its design peak power and rated average power simultaneously. The pulse compression system showed superior performance both over clutter and in the clear. The only possibly deleterious effect of the pulse compression system was the displaying of range sidelobes on strong moving targets. Spectral calculations and measurements show the pulse compression spectral energy concentrated near the carrier. The envelope of the pulse compression spectrum falls below the envelope of a conventional spectrum for frequencies removed from the carrier, even though the shoulders of the pulse compression spectrum are wider. Inversion of sweep sense provides another dimension of interference discrimination not available to conventional radars. Modified author abstract