Point sensor for vertical directional noise environments

Abstract

A new point-sensor concept is defined, evaluated, and shown to have enhanced performance, relative to other simple configurations, in ocean environments which exhibit noise vertical directivity. This property is characteristic of deep ocean areas at low frequencies, and the successful exploitation of the acoustics of such an environment imply special sensor and processing design factors. The concept treated in this paper involves three orthogonal, directional elements and a single omnidirectional element, with all elements colocated. The receiver utilizes cross correlation between one directional element, oriented along the vertical, and the other elements as well as individual element power spectra. The outputs are suitably combined to produce log-likelihood statistics and maximize detection probability for weak signals arriving along angles at or near the noise peak. Analytical results are presented for detection performance of this concept relative to other concepts in representative signal and noise environments. [Work supported by Naval Electronics Systems Command, Code 320.]