Abstract: A signal detector for detecting an information component of a passive radar detection signal, comprises a sampler operable to obtain a sample segment, in time domain, of a radar detection signal, a signal processor operable to identify a relatively high power periodic component of the sample segment signal spectrum in contrast to a relatively low power information component of the sample segment signal spectrum, and a signal rejector operable to window the detection signal with respect to the identified periodic component, to retain parts of the signal not interfered by said periodic component.

Abstract: A signal detector for detecting an information component of a passive radar detection signal, comprises a sampler operable to obtain a sample segment, in time domain, of a radar detection signal, a signal processor operable to identify a relatively high power periodic component of the sample segment signal spectrum in contrast to a relatively low power information component of the sample segment signal spectrum, and a signal rejector operable to window the detection signal with respect to the identified periodic component, to retain parts of the signal not interfered by said periodic component.

Abstract: A continuous wave frequency shift-keyed radar apparatus comprising means for changing the frequency of the transmitted continuous wave periodically and in a pseudo-random sequence, means for mixing the received wave with the transmitted wave or a delayed version thereof to produce a beat signal, means for sampling the beat signal, in respect of each period of simultaneous transmission and reception at the same frequency, means for reordering successive segments of the sampled beat signal to put them in sequential frequency order, and means for transforming the reordered segments to provide an output signal in the range domain.

Abstract: A scan-to-scan integrator for use in radar apparatus comprises means for defining a search window for use in verifying a candidate detection. The window is bounded by the intersection of a first zone and a second zone, wherein the first zone comprises a rectangular reference frame aligned detection window, and the second zone comprises a range estimate tolerance region defined by a range estimate for the candidate detection and predetermined tolerance limits.