At-Sea Measurements of Diver Target Strengths at 100 kHz: Measurement Technique and First Results

摘要

During a recent at-sea trial of a diver detection system, the opportunity was taken of developing a technique for in-situ measurement of diver target strengths. The technique was based on making the diver perform circular maneuvers in front of the sonar to present all aspect angles to the sonar. The experimental set-up employed, the procedure employed, how the set-up complied with the far-field requisite and how the multipath effects were eliminated are discussed. A transformation of coordinates (by change of origin), the inverse transformation and how the transformation was employed in aspect angle estimation are examined. The paper then looks at application to the case of a diver with air tanks, exhaling clouds of bubbles into the water column, and how a target tracker was developed to locate the diver.