초록 ▼

A low PRF pulse doppler radar system utilizing a VIP digital filter bank signal processor to suppress echoes from terrain, rain, and chaff, and pass echoes from aircraft moving at higher speeds is disclosed. Each of a plurality of VIP filters individually provides high attenuation to undesired signa

A low PRF pulse doppler radar system utilizing a VIP digital filter bank signal processor to suppress echoes from terrain, rain, and chaff, and pass echoes from aircraft moving at higher speeds is disclosed. Each of a plurality of VIP filters individually provides high attenuation to undesired signals over designated frequency bands, the width of which are a large fraction of 1/Tav where Tav is the average interpulse period. Little or no attenuation of desired signals having doppler frequencies greater than 1/Tav occurs. The outputs of the plurality of filters are desensitized to prevent false alarm from clutter, and the presence of a desired radar pulse echo is determined by a comparison with a threshold level.

대표청구항 ▼

In a pulse doppler radar system, the combination comprising: means for generating radar pulses at predetermined variable interpulse periods; means for receiving the echo pulses; means for converting the sampled pulses to digital words; a plurality of digital filters, each filter having I and Q compo

In a pulse doppler radar system, the combination comprising: means for generating radar pulses at predetermined variable interpulse periods; means for receiving the echo pulses; means for converting the sampled pulses to digital words; a plurality of digital filters, each filter having I and Q components; said plurality of digital filters being operative to receive the digital words in sequence at the sample times, each of said filters being constituted to provide attenuation to pulse echoes from objects less than a predetermined velocity over a different predetermined doppler frequency band, each said filter having a single rejection notch, the width of which is a large fraction of the reciprocal of the average period between the sampled pulses, each said filters being constituted also to provide substantially no attenuation to pulse echoes having doppler frequencies greater than the reciprocal of said average period; means responsive to clutter interference in each filter to desensitize the outputs of the respective filter to prevent false alarms from clutter; and means to detect the output values of the desensitizing means.