Optimization method of operating depth for transmitted acoustic detection of underwater targets

In the transmitted acoustic detection for underwater targets, low signal-to-interference ratio (SIR) is the most critical challenge to target detection. The performance is closely influenced by the depth of sonar source, target and receiver. By optimizing the operating depths, the SIR and detection performance can be significantly improved. A performance evaluation model of bistatic transmitted sonar systems was established based on the sonar equation. Target navigation logic was integrated to predict the probability distribution of potential target positions. An objective function based on weighted sum of SIR was formulated to identify the optimized range and the global optimal operating depth. Simulations and statistical analyses were conducted in two distinct environments to demonstrate the improvements of SIR. Furthermore, the proposed method was found not sensitive to mismatches in target parameters, seabed sediment, and environmental depth, showing good robustness. These results highlight the potential for significant enhancement in sonar detection capabilities through optimization of operating depths.