Abstract: A method and apparatus for preventing the occurrence of range ambiguities and Doppler ambiguities in both a radar and sonar environment. A series of N pulses are produced, each of which contains a number of contagious subpulses. Each of the subpulses exhibit a different frequency than the remaining subpulses in that particular pulse. Furthermore, the order of appearance of the subpulses in each of the pulses is unique with respect to the remaining pulses in the series. A matched filter receiver and Doppler processor are used to provide auto correlations and cross correlations to prevent the range ambiguities and Doppler ambiguities.

Abstract: A factored matched filter/FFT radar Doppler processor for reducing the le of clutter components contained in radar signals. The processor includes a matched Doppler filter, having a filter response matched to the spectrum of the clutter components, through which the radar signal is passed. The filtered output of the matched filter is further filtered by a coherent integration filter to further reduce the level of the clutter components.

Abstract: An apparatus for nulling signals from unwanted interference sources. The aratus includes an N element antenna array interconnected with a weighted Butler matrix. The outputs of the Butler matrix are applied to an adaptive reducing matrix having outputs (x.sub.2, . . . ,x.sub.L), with L<N, where is the main antenna channel signal, x.sub.1, and (x.sub.2, . . . ,x.sub.L) are the signals required to null the effects of jammer signals received in the sidelobes of the main antenna channel. The signals (x.sub.1, . . . ,x.sub.L) are directed to the inputs of a sidelobe canceller.