Investigation of Potential Mapping Products Based on Acoustic Imagery from AN/SQS-53B ASW Sonar.

Abstract : Naval Research Laboratory (NRL) personnel collected acoustic backscatter data using the AN/SQS-53B ASW sonar on board the USS Monterey(CG-61) during transits of the Red Sea in November and December 1995. This report presents preliminary results on the potential of this type of data as a source of acoustic imagery for seafloor mapping. The AN/SQS-53B sonar operates at a frequency of 3.5 kHz giving it the ability to operate at long ranges. Its 12 geo-stabilized beams facilitate collects of multiple aspect angle coverages of the same area of the seafloor that the ship transits. The NRL data acquisition system works in conjunction with the sonar operation without interference. A preliminary comparison of the AN/SQS-53B sonar data with multibeam bathymetry, taken simultaneously by the Naval Oceanographic Office, shows that acoustic backscatter generally correlates with seafloor relief in both deep and shallow water. This observation leads to the main conclusion that an acoustic backscatter mapping product based on data collected during routine operations could enhance the utilization of the sonar in its primary mission of ASW, i.e., determination of optimum look-direction for ASW sonars and detection targets in high bottom-reverberation areas. A further implication of these results is that U.S. combatants operating in unfamiliar or poorly charted areas will have an on board capability to detect shoals or other navigational hazards well in front of the ship's movement.