Radar reconnaissance system for track vehicle recognition

Claim 1

In a pulsed Doppler radar system providing at least one received signal corresponding to a discrete range bin, the combination comprising: first means responsive to said received signal to provide a second signal the components of which are of doubled frequency as compared to said received signal; multiplier means responsive to said received signal and to said second signal to provide a third signal which is the product of said received and second signals; filter means responsive to said third signal to produce a fourth signal which contains substantially only those spectral components corresponding to the tracks of a track vehicle; first and second amplitude detectors responsive to said received and said fourth signal, respectively, to provide demodulated received and fourth signals; second means responsive to the outputs of said amplitude detectors to produce a fifth signal which is the quotient of said demodulated fourth signal divided by said demodulated received signal; and third means for comparing said fifth signal with a fixed threshold representative of the average ratio of the amplitudes of the signals reflected by the vehicle body to those refelected from a track of said vehicle, said third means providing an output indicative of the presence of said track vehicle at the range corresponding to said received signal range bin.