Processing of SeaMARC swath sonar data

A description is given of the acquisition and processing of data collected by a class of high-resolution sonar systems, the SeaMARC (seafloor mapping and remote characterization) swath mapping sonars. The SeaMARC system has two basic configurations: deep-towed, which acquires high-resolution backscatter imagery at slow survey speeds, and shallow-towed, which simultaneously acquires lower resolution backscatter and bathymetric information at higher speeds. Processing techniques applied to the data after acquisition are fairly independent of the initial towing configuration and include: compaction of the original data by decimation; radiometric corrections (noise removal, destriping, beam pattern correction, and contrast enhancement); derivation and merging of vehicle navigation with the sonar data; integration of backscatter and bathymetric information; and geometric corrections for plotting data in geographic coordinates.