Littoral Environment Parameter Estimation from Bistatic and Multistatic Fleet Air Antisubmarine Warfare (ASW) Acoustic Reverberation Data

The Navy uses collections of sonobuoy sources and receivers to search for enemy submarines. These systems can potentially cover large search areas in a relatively short time. However, like all sonar systems, performance is very difficult to predict either in-situ or after-the-fact. In the Phase 1, RDA Inc. successfully demonstrated the ability to make calibrated measurements of the environment during the ASW tactical search stage. Calibrated measurements of ambient noise and reverberation level are made using SEA, ADAR, or VLAD sonobuoys. Transmission loss is measured directly using either the SEA buoy or a combination of low-power sources and tactical sonobuoys. ASW system performance is calculated and relayed as an updated in-situ field Pd, a detection coverage graph for each sensor and the entire field, and an improved acoustic model of the mission op-area. In the Phase 2, RDA will implement the designs resulting from Phase 1. These designs will be implemented in software and integrated into RDA’s Low-Cost Advanced Processor (LCAP), and will be available for in-flight use aboard the Navy’s P-3 aircraft. LCAP provides a 32 analog or digital channel interface to the P-3’s sonobuoy receivers, and records, processes, and displays the data in-situ or post-flight.