ASA 126th Meeting Denver 1993 October 4-8

4pUW9. Signal-to-noise improvement for higher-order correlators with one-dimensional prefiltering.

Lisa A. Pflug

Naval Res. Lab., Stennis Space Center, MS 39529-5004

Juliette W. Ioup George E. Ioup

Univ. of New Orleans, New Orleans, LA 70148

Robert L. Field

Naval Res. Lab., Stennis Space Center, MS 39529-5004

Previous work by the authors has shown that prefiltering when used in conjunction with higher-order correlators possesses potential detection advantages over the ordinary cross-correlation detector for bandlimited transient signals in noise for active (known source) and passive (unknown source) sonar. Preliminary simulation results have been presented [Ioup et al., J. Acoust. Soc. Am. 92, 2417(A) (1992); Ioup et al., Proceedings of the IEEE Signal Processing Workshop on Higher-Order Statistics, 7--9 June 1993]. Additional research has been completed, including a systematic and quantitative study using three different filter levels. Eight test signals are presented in the study: Several very low-frequency signals, a pulse, a 50-Hz sinusoid, a resonating sinusoid, a FM linear sweep, and a nonlinear FM sweep. SNR gain comparisons between the detectors are made for P[sub d]=0.5 and P[sub fa]=0.001. Significant SNR gains are evident for both the known and unknown source models with the tricorrelation detector exhibiting the largest gains. For all the test signals, the tricorrelation detector outperforms the cross-correlation detector for the unknown source model, and outperforms the matched filter for seven of the eight test signals for the known source model. [Research supported by Office of Naval Research, Program Element 61153N, with technical management provided by NRLSSC.]