Performance assessment of propagation models in AESS-6.0

Abstract

A set of AESS propagation-loss predictions has been generated for typical operational scenarios in both deep and shallow water, for two sonar frequencies (500 and 3500 Hz) and for several source-receiver combinations. Reference solutions to all test problems were obtained with the GRAB range-dependent ray-trace model, which, in turn, has been thoroughly benchmarked against other acoustic models from the SACLANTCEN model library. The validation of the six acoustic models in the Allied Environmental Support System (ASTRAL, MOCASSIN, PE, PROLOS, RAYMODE, SUPERSNAP) has identified several shortcomings in the general model performance. Both implementation errors and inconsistent use of data base information are shown to be the main causes of observed prediction errors. These deficiencies, however, are all correctable through close collaboration between model developers and AESS system engineers. Detailed conclusions and recommendations are provided.