Optimization of active sonar parameters in a measured environment

Sonar operation in coastal waters is challenging due to high false alarm rates and strongly varying sonar conditions. Optimal choices for sonar design and pulse characteristics depend strongly on target location and velocity, as well as the present environment. Given a description of the target and environment, acoustical models may estimate sonar performance for different sonar parameters. Updating sonar parameters to best meet shifting sonar conditions impose an unnecessary workload on operators and must be automated for unmanned systems. We suggest an optimization approach that takes into account both a variable environment and a random target. An acoustic ray trace model is run in all directions for a large number of different environment, target, and sonar realisations. Target parameters such as Doppler and aspect are modelled, and optimal sonar parameters are determined. The method is demonstrated for a littoral test case, where both the sonar design and its pulse parameters are optimized. The design takes into account whether the sonar is towed or hull-mounted, and its frequency. The pulse parameters include pulse length and pulse repetition time. The method can easily be extended to other sonar parameters, but the main intent here is to demonstrate the approach.