Use of the AN/AQS-20A tactical mine-hunting system for on-scene bathymetry data

The effectiveness of mine countermeasures is dependent, in part, on how well warfighters know the ocean environment. Often, knowledge is outdated, in error or absent, requiring rapid environmental assessment on-scene. One way to obtain this assessment is to make dual use of the tactical data from military sensors to extract environmental information. Here, we discuss calibration and data uncertainty associated with using the multibeam volume search sonar onboard a AN/AQS-20A towed mine hunting system to extract multibeam bathymetry data based on data sets obtained from five demonstration flights conducted off the coast of Panama City, Florida. We compare the extracted bathymetry to overlapping data sets from dedicated multibeam echo-sounder systems and find a bias correction for the system. We also identify inaccurate knowledge of the sound velocity profile as a source of measurement error, discuss mitigation of it where possible, and assess how this error affects the uncertainty of the bias correction.