Beyond interferometry, resolving multiple angles-of-arrival in swath bathymetric imaging

This paper presents a new swath bathymetric sidescan sonar concept that extends the single angle-of-arrival measurement technique used in interferometric sidescan to multiple angles-of-arrival. The new sonar concept utilizes a small array of vertically stacked sidescan transducer elements and affords high resolution 3D imaging and mapping of underwater geometries difficult to address using simple interferometry. The focus of the paper is the presentation of 3D sector-scan and sidescan results obtained using a prototype six element 300 kHz sonar. Results are presented for both target imaging and bottom mapping experiments.