Abstract: A method includes communicating a first signal at a transmitter. The first signal has a first frequency. The method also includes receiving a second signal at a receiver. The second signal has a second frequency, and the second signal comprises the first signal converted from the first frequency to the second frequency. In addition, the method includes determining whether the transmitter and receiver are functional using at least one of the first and second signals.

Abstract: A method includes communicating a first signal at a transmitter. The first signal has a first frequency. The method also includes receiving a second signal at a receiver. The second signal has a second frequency, and the second signal comprises the first signal converted from the first frequency to the second frequency. In addition, the method includes determining whether the transmitter and receiver are functional using at least one of the first and second signals.

Abstract: Presented in this invention is a technique for producing a null in the frequency spectrum of an FM signal pulse, the null matching an interference that has been superposed on the signal pulse. By matching the null to the interference, the energy in the frequency spectrum is shifted in such a way that when the interference is rejected by a band elimination filter, none of the useful energy would be discarded along with the rejected interference. Consequently, a signal resulting from the technique has a much higher amplitude than previously filtered signals. This leads to the signal being more readily recognized by detection systems, such as a radar detector.

Abstract: An ADPCA subsystem includes a weight processor for weighting the delta channel signal according to the results of an adaptive algorithm to which the output of a DPCA vector combiner is input. An AMTI vector combiner is connected to the output of the DPCA vector combiner to form the filter output. The delta channel signal is time delayed and samples of the delta channel signal are collected by the processor together with a sum channel sample and a residue sample, in order to apply the proper weights to the undelayed and delayed delta channel samples. The output of the ADPCA weight processor therefore provides an optimum correction signal to the vector combiner.

Abstract: Prior art radar systems do not adapt the transmitted signal to avoid the interference bands but only filter the unadaptive receiver signal to eliminate the interference with resulting loss in detectability and distortion that in turn causes loss in resolution and increased ambiguity. The present invention allows a radar system to operate in an electromagnetic environment where co-channel narrow band interference is present, without loss of detectability, resolution and ambiguity. The present invention system adapts the radar transmitted signal so that its spectral energy is significant only in the interference free portions of the radar channel. It next adapts the receiver to detect this transmitted spectrum and then equalizes the signal by means of transversal equalizer coefficients to reduce distortions to the signal sidelobes.