Radar MTI processor with CFAR

Claim 1

For use with a pulse doppler radar, a received signal processor affording MTI operation and CFAR capability comprising: a. MTI cancellation circuit means having said received signals applied thereto and providing an MTI signal of level in accordance with a first predetermined gain factor (α) at the MTI cancellation frequency and of substantially higher level at frequencies displaced therefrom; b. blanking circuit means having said received signals applied thereto and providing a blanking signal of level in accordance with a second predetermined gain factor (β) which is substantially uniform with frequency, the magnitude of β being significantly greater than that of α; c. pulse compression means and video detection means having applied thereto said MTI and blanking signals, and providing MTI video and blanking video signals by compression and detection of signals from said cancellation circuit and said blanking circuit means respectively; d. first threshold means connected to receive at least the MTI video signal from said detection means and operative to pass only such thereof as exceeds a first threshold; and e. second threshold means connected to receive said MTI video signal and operative to pass only such thereof as exceeds said blanking video signal as a second threshold, whereby false alarms which might otherwise result from high clutter levels in said MTI video signal are prevented by the correspondingly high levels of said blanking video signal applied as said second threshold.