Adaptive pulselength correction (APLECORR): a strategy for waveform optimization in ultra-wideband active sonar

This paper describes a technique for optimizing the detection index (and as a result, the probability of detection) of an active sonar in doubly-spread channels by proper distribution of transmitted energy in the band. The method requires measurement of reverberation and ambient noise spectra in the band, and a prediction of signal energy as a function of frequency for a trial waveform. The amount of improvement over the trial waveform is high when there are large fluctuations of the reverberation-to-ambient noise ratio in the band. Thus, the method is most useful for wideband systems