Multistatic Transmission Loss (TL) Estimation

Signal Systems Corporation will extend its BAyesian Tactical Transmission Loss Estimator (BATTLE) technique to reduce clutter in enhanced Multistatic Active Coherent systems by using direct blast and Airborne eXpendable BathyThermograph (AXBT) data that are measured nearby each sonar detections acoustic propagation path. After matching the in-situ data to physical parameters that control Transmission Loss (TL), BATTLE estimates the two-way TL for a detection location using different target hypothesis depths and rejects snippets that are infeasible as a submarine target echo. In order to control aircraft computational costs and extend BATTLE to include in-situ environmental hypothesis generation, we will develop a non-linear regression technique to replace the ocean propagation steps in the run-time BATTLE component.Our approach measures the variability of transmission loss during the mission and the degree of variability from ocean physics models. BATTLE automatically adjusts the clutter suppression thresholds to reflect the variability and uncertainty in the ocean propagation conditions encountered during the mission. During Phase I, we will investigate methods to reduce the variability in TL estimation. Our approach to TL based clutter suppression has already shown promise on at-sea data sets.