Comb waveforms for sonar

Comb waveforms allow the simultaneous use of a set of individual waveforms to achieve improved resolution in range, Doppler, or both. In this paper a new comb waveform is presented which is based on the use of pairs of triplets of the single-frequency spectral lines which constitute the comb. This "triplet-pair" comb has several desirable properties namely, a relatively high power efficiency, relatively high resolution in Doppler, and a moderately good resolution in range (delay). This new waveform is compared with several standard waveforms using a set of system parameters commensurate with current Naval interests. Performance of these waveforms in reverberation is compared via the Q-function (amount of suppression vs. Doppler). Performance of these waveforms in ambient noise takes into account the relative efficiency with which they are able to use available sonar projector power levels. The "triplet-pair" waveform is seen to be competitive with the other Doppler-sensitive waveforms, having slightly lower performance in reverberation-limited conditions, and having slightly higher performance in ambient-noise-limited conditions, for the particular system parameters used in the comparison.