Sonar Detection of Buried Targets at Subcritical Grazing Angles: APL-UW Compnent

摘要

The objective of the joint project (APL-UW and Naval Surface Warfare Center Panama City) was experimental investigation of subcritical buried target detection through rippled sediment/water interfaces. The APL-UW portion of the project had two main components: (1) measurement of the ripple profile and small scale roughness for use in modeling subcritical detections; and (2) collaboration with NSWC-PC in carrying out Synthetic Aperture Sonar (SAS) experiments, in analysis of the acoustic data, and in comparisons of the results to model predictions. The focus for the first component was deployment of a new digital stereo camera system (first used in the Sediment Acoustics Experiment in 2004 -SAx04) in the Gulf in support of an AUV mine-hunting exercise conducted by NSWC-PC in May 2006. This system gives an estimate of the small-scale 1-D roughness spectrum. The second component focused on measurements of both small scale roughness and subcritical buried target detections in controlled laboratory-type experiments carried out in the NSWC-PC test pond. Data were obtained on both spherical and cylindrical targets. Data from these targets were used for comparison with model predictions. Several models were tested experimentally and consistency between models shown. Together the models represent a hierarchy of sophistication that can be applied to buried target detection depending on the needs of a particular program.