Underwater signal detection in partially known ocean using short acoustic vector sensor array

A new narrowband signal detection method called subspace detection (SD) was proposed recently for achieving improved detection performance in shallow ocean. The SD method requires the knowledge of mode functions and modal wavenumbers of the ocean channel. In this paper we present three new methods of narrowband signal detection in a partially known ocean using an array of acoustic vector sensors (AVS). These methods require less prior information about the ocean channel; and yet they provide a better performance than SD especially at higher signal frequencies or shorter array lengths. Two of the new methods require only knowledge of sound speed at the sensor locations. The performance of the proposed methods is frequency-independent. These methods can be used with arrays in either horizontal or vertical configurations, and with either linear or circular geometries.