False alarm rate and detection probability in a receiver

Abstract

An improved performance receiver associated with a radar system for detecting targets over a specified range area whereby the receiver, which is responsive to a return signal corresponding to an actual target or a false target, includes: an attenuator for attenuating an amplitude associated with the return signal; sensitivity time control means coupled to the attenuator wherein the attenuation is coordinated to the sensitivity time control means and the attenuation of the return signal is selectively variable such that the amplitude of the return signal is attenuated to a first level at closer ranges of the specified range area and attenuated to a second level at farther ranges of the specified range area, the first level being greater than the second level; a mixer for downconverting the return signal to a signal exhibiting an intermediate frequency; a detector for extracting a target video signal from the downconverted return signal; detection threshold setting means for generating a detection threshold signal; and a comparator for comparing the target video signal to the detection threshold signal to generate a comparator output signal indicating whether the target video signal is at least greater than the threshold detection signal; wherein the threshold associated with the detection threshold signal is selectively variable such that the threshold may be varied in coordination with the varied attenuation of the amplitude of the return signal provided by the sensitivity time control means in order that a probability of false target detection and/or a probability of actual target detection are substantially improved.