Ambiguity function properties of frequency-hopped radar/sonar signals

Properties of the ambiguity function for frequency-hopped radar/sonar signals with firing orders based on Costas arrays are analyzed. The locations of range-Doppler coincidence values are obtained using ambiguity function plots of long-duration signals containing large numbers of cycles per subpulse. The general shape of the ambiguity function for short-duration signals containing small numbers of cycles per subpulse is deduced from that of the corresponding long-duration signal. Costas sequences with closely spaced coincidence locations are shown to produce slightly higher sidelobe levels than Costas sequences with more widely spaced coincidence distributions