Improved detection performance of an FM signal by autoregressive spectral analysis

Conventional narrowband detectors suffer large losses in detection performance when the assumed sinusoidal receive signal is actually frequency modulated. Such would be the case for the detection of a maneuvering target by a passive sonar system. Based upon autoregressive spectral analysis a detector is presented which is nearly invariant to frequency modulation. In fact, for a large enough frequency modulation the autoregressive detector yields about a 4 dB improvement in detection performance over the conventional narrow-band detector. Furthermore, the autoregressive detector is a CFAR receiver and requires less computation and storage than a conventional narrow-band detector. Thus, the autoregressive detector should be an attractive complement to a conventional narrowband detector.