US Navy looking into ‘sway problems’ of littoral combat ship minehunting sonars

The U.S. Navy said that it has improved its ability to track down mines after completing a series of sonar tests at Carderock’s David Taylor Model Basin in Bethesda, Maryland.

The navy’s unmanned maritime systems program office along with Naval Surface Warfare Center (NSWC) Carderock Division tested the AN/AQS-20A Variable Depth Sonar (VDS), the minehunting sonar for the Navy’s Littoral Combat Ship (LCS) program that provides detection and classification of mines through imaging sonars, signal processing and computer algorithms.

Previously collected data indicated that the AN/AQS-20A, when towed, exhibited an off-center bias, or “sway,” when compared to its tow platform. That sway impacts the sonar’s target localization capability, i.e. its ability to determine the position of mine-like objects detected in the water or on the sea floor.

“Testing at Carderock’s impressive basin was part of the Navy’s proactive approach to identify the root cause of this occurrence,” said Capt. Bill Guarini, PMS 406 program manager. “This new data will help us deliver improved mine-hunting capability to our sailors.”

Led by NSWC Carderock with personnel support from the Navy’s unmanned maritime systems program office, NSWC Panama City division and an industry partner, the testing investigated the hydrodynamic behavior exhibited by the AN/AQS-20A VDS when towed by various surface and semi-submersible vehicles.

Data collected from the tests will help determine the root cause of the sway phenomena and improve the sonar’s detection algorithms. Based on the findings, recommendations for corrective action or further testing will be presented to the LCS program office and NAVSEA’s engineering directorate.