Determination of Amplitude Distribution to Improve Along-track Resolution for Multi-receiver SAS

Abstract

This paper proposes a solution for determining an amplitude distribution to enhance along-track resolution and reduce the peak side-lobe ratio (PSLR) when reconstructing images in multi-receiver synthetic aperture sonar (SAS). Based on analysis of the mathematical expression of the beam pattern and on simulation results, the proposed solution provides the amplitude distribution generating the highest along-track resolution and a PSLR that is less than the required value. With separation of the amplitude distribution into the product of two distributions (the real physical array and a virtual array from pings), the proposed solution decreases the number of investigations needed to determine the optimal amplitude distribution. The improvements in the along-track resolution (or half-power beam width) are evaluated by comparing the beam pattern derived from the proposed solution against the pattern from a conventional solution with real sound velocity data.