Broadband low frequency sonar for non-imaging based identification

A new approach to underwater object identification is presented that aims to capitalize on structural acoustic features found in targets at low frequencies. In order to use these features for identification purposes, multi-aspect scattering cross-sections must be extracted over a broad range of frequencies. In this paper, we describe a system created to do this. It employs new low frequency source technology based on CYMBAL arrays and an unconventionally large vertical receive array. Data are acquired in a coherent fashion and synthetic apertures are used to extract multi-aspect target scattering cross-sections*.