An interference signal suppression system and method that suppresses coherent jamming signals. The system comprises first and second receiving antennas that are physically separated from each other to generate non-coherent received signals of interest. The antennas are positioned to receive communication signals that are jammed with coherent energy. The separation distance is typically 40 to 50 wavelengths of the non-coherent scattered wave radio frequency signals. Phase and amplitude adjustment circuitry is provided that alters the phase and amplitude of the received signals such that the coherent received signals are balanced and out-of-phase. These signal are then summed in a summing circuit and the output of this circuit generates signals wherein the coherent signals are nulled and the non-coherent signals are detectable. The signal suppression system and method is independent of the direction of arrival of the coherent signals, which overcomes limitations of conventional techniques.

A method of operating a radar to track echo signals from a target in the presence of a barrage jammer is shown to comprise the steps of actively determining the apparent direction of the combination of echo signals from a target and jamming signals, passively determining the actual direction and average power of a barrage jammer, calculating, from the foregoing, the actual direction of the target and instituting range and angle tracking of the target when the target is clear of the jamming signals.

Improved radar system performance in a jamming environment is achieved by detecting the AM difference frequency produced by the beating of the desired radar signal with the jamming signal and applying same to one input of a balanced modulator while simultaneously applying the received signal (containing both the desired radar signal and the jamming signal) to the other input of the balanced modulator whereby the output from the balanced modulator contains the desired signal but not the jamming signal.

A polarization measurement system and method that determines the polarization of a received signal within one received pulse. The polarimeter accepts series of samples representing horizontal and vertical signal components representing the polarization of a received signal. The samples are discrete time measurements, with each sample representing a magnitude separated in time by a predetermined angular resolution. The samples are combined with other samples in numerous sets of calculations operating in parallel, the various sets of calculations employing different transfer functions, so as to produce numerous series of output values. Characteristics of these series are examined to select a particular series, and thus select the transfer function which provided the series having a desired characteristic such as a best null. The parameters of the transfer function which provides the desired characteristic provide information representative of the signal polarization.