Method of pre-processing acoustic signals received from an ensonified region of an underwater environment

Abstract

A method of pre-processing acoustic signals received from an ensonified region (104) of an underwater environment (102) for passive detection of an object (106, 108) in the underwater environment (102). The method comprises generating (404) an acoustic B-scan (500) in respect of a predetermined time frame, and selecting (406) a temporal portion (502) of the acoustic B-scan (500) in accordance with a predetermined selection criterion. The method also comprises compressing (408) the selected temporal portion (502) of the acoustic B-scan (500) to provide a compressed acoustic B-scan (510), and applying (410) a B-scan background mask (512) to the compressed acoustic B-scan (510) to suppress any historic reflectivity samples of the compressed acoustic B-scan (510) and to provide an extant compressed acoustic B-scan (524), A dynamic range of the extant compressed acoustic B-scan (524, 600, 602, 604) is then suppressed (412).

Dependencies are inferred from the claim text.