Determination of the Time of Energy Return from Beamformed Data

Multibeam bathymetric sonar systems such as the Sonar Array Survey System (SASS), the Sea Beam, and the Sea Beam 2000, are capable of collecting data which, after proper processing, may be used to map the bottom of the ocean. The sonar energy form the projector array impinges the ocean bottom as a narrow swath perpendicular to the ship's heading. The echo from this swath is received by an array of hydrophones mounted athwartships. Beamforming permits good reception of energy propagating in a certain direction while attenuating energy propagating in other directions, and may be performed in hardware or software. Beamformed data gives a time history of the energy received from each look direction