Radar ambiguity function, time-varying matched filter, and optimum wavelet correlator

Abstract

We review the relation between the radar ambiguity function and the matched filter, and then introduce a geometric concept of the matched filter as a slice of the ambiguity function along a frequency-shift line. With the help of this geometric concept, the conventional matched filter can be generalized to a time-varying matched filter, which is equivalent to the optimum time-frequency correlator and can be implemented with wavelet transforms. The application of the optimum wavelet correlator to the inverse synthetic aperture radar is illustrated.