Simulation of Active Sonar Bottom Clutter for Fleet Trainers

In response to a critical Navy need for improved simulation in active sonar trainers, techniques for simulating ocean bottom clutter were developed at the Johns Hopkins University Applied Physics Laboratory (APL). The algorithm versions passed independent evaluation and were transitioned to the Navy's trainer implementation teams. The first version of the algorithm was designed for the Navy surface ship 53C sonar system and transitioned as part of the Advanced Capability Build 2011 (ACB-11). APL worked closely with the implementation contractor to ensure that the simulation output was sufficiently realistic to provide useful training. Upgrades were provided for ACB-13 in 2012. A third version of the algorithm was designed for the Navy's Naval Air Systems Command sonar system simulation Common Acoustic Synthetic Environment (CASE). This includes both the Multistatic Active Coherent and the Airborne Low-Frequency Sonar systems. APL worked closely with the CASE implementation contractor and participated in the acceptance testing by Navy operators. The operators rated the results as sufficiently realistic. A final revision of the algorithm was successfully evaluated independently and readied for transition to ACB-15.