Evaluation of ocean acoustic reverberation models

Judicious design and use of active ocean sonar equipment requires being able to predict environmental acoustic parameters such as propagation loss and reverberation. Although several numerical models have been developed to meet this need, a persisting problem is that the models have not undergone sufficient evaluation. The problem is especially severe with regard to reverberation. Within the underwater acoustics community, it is not adequately well understood what aspects of the physics, what numerical procedures, and what values of environmental parameters are needed in order to obtain reliable predictions of reverberation, consistent with engineering trade-offs between accuracy and computation cost. This paper describes some experiences and lessons learned during a model evaluation exercise in which predictions by two sonar models (NISSM II and LIRA) were compared to each other and to data.