Navy asks Raytheon to upgrade AN/AQS-20 mine-hunting system with high-resolution synthetic aperture sonar

April 2, 2021
The AN/AQS-20 is a mine-hunting and -identification system aboard the Navy's Littoral Combat Ship that can detect, classify, and pinpoint enemy mines.

WASHINGTON – Counter-mine experts at Raytheon Technologies Corp. will upgrade the U.S. Navy AN/AQS-20 mine-hunting sonar system to enhance the system's imaging sonar resolution under terms of a $66.5 million contract announced Wednesday.

Officials of the Naval Sea Systems Command in Washington are asking the Raytheon Missiles & Defense segment in Portsmouth, R.I., to upgrade 10 legacy AN/AQS-20A mine-hunting sonars to the AN/AQS-20C configuration.

While the legacy AN/AQS-20A has four separate sonars in a compact, lightweight and hydro-dynamically stable towed body, the AN/AQS-20C adds a fifth sensor -- a synthetic aperture sonar that provides the highest possible resolution for acoustic identification of underwater threats like submerged mines.

The AN/AQS-20 is a mine-hunting and -identification system aboard the Navy's Littoral Combat Ship. It has acoustic and identification sensors housed in an underwater towed body. The acoustic sensors detect, classify, and pinpoint bottom, close-tethered, and volume enemy mines in one pass.

Related: Navy asks Raytheon to upgrade the AN/AQS-20 helicopter- towed mine-hunting sonar in $20.7 million deal

The AN/AQS-20A uses imaging sonars, signal processing, electro-optical sensors, and computer algorithms to provide real-time, computer-aided detection and classification of threat mines. It automatically localizes mine-like objects and provides the operator with a visual image and a contact data list. All mission data is recorded for post-mission analysis.

The combination of sidescan, forward-looking, and gapfiller sonars enables the AN/AQS-20A to detect and classify mine-like objects from the seafloor to the near surface in one pass.

The system also has an electro-optical identification capability that delivers high-definition images of bottom mines using Streak Tube Imaging Laser technology. This provides the operator with range and contrast data for post-mission analysis to aid in mine identification.

Related: Raytheon to upgrade sonar systems in towed mine-hunting remotely operated vehicle

The AN/AQS-20C is platform-agnostic and can be integrated onto various tow vehicles. It operates from on Navy MH-53E and MH-60S helicopters, from the AN/WLD-1 remotely operated underwater vehicle, and from the Littoral Combat Ship's mine-countermeasures unmanned surface vessel. The system can find and neutralize sea mines placed as deeply as 450 feet deep.

It is a key element in single-sortie detect-to-engage capability, which combines the search, detect, identify, and neutralize elements of the Littoral Combat Ship's mine-countermeasures package.

The AN/AQS-20C completed developmental testing in February 2019, has been integrated aboard the Littoral Combat Ship. It is 10.5 feet long, 15.5 inches in diameter, and weighs 975 pounds.

Related: Northrop Grumman to upgrade Navy's AN/AQS-24 airborne and surface mine-hunting sonar system

In January 2020 Raytheon delivered its 10th AN/AQS-20C minehunting sonar system to the U.S. Navy. The sonar-towed body was transferred officially to the Naval Surface Warfare Center Panama City Division in Panama City, Fla.

The system is the program of record for the Navy's Littoral Combat Ship mine countermeasure mission package, and is moving toward initial operating capability.

For more information contact Raytheon Missiles & Defense online at, or Naval Sea Systems Command at

Voice your opinion!

To join the conversation, and become an exclusive member of Military Aerospace, create an account today!