AN/AQS-20 Minehunting Sonar

The AN/AQS-20 Minehunting Sonar enters the water. (Photo: US Navy)

The U.S. Navy's standard for minehunting, the AN/AQS-20 is an advanced minehunting sonar system that has been designated as the minehunting sonar for the Littoral Combat Ship's mine countermeasure mission package.

The AN/AQS-20 incorporates four separate sonars in a compact, lightweight and hydro-dynamically stable towed body. It uses state-of-the-art imaging sonars, signal processing and computer algorithms to provide real-time, computer-aided detection and classification against the full spectrum of threat mines. The AN/AQS-20 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.

Reducing Risk Through Operations Consolidation, Agility

The AN/AQS-20's computer processing power and advanced signal processing, coupled with its portability, reduces the amount of time required to search an area while significantly increasing search-rate agility. By reducing the size of the platform and the number of crew required to deploy the system, the AN/AQS-20 safely and efficiently consolidates expansive mine-sweeping operations that previously required a large warfare ship manned by more than 80 crew members.

This low-risk approach gives the fleet an organic mine countermeasures capability in the near term that meets all Navy requirements. The AN/AQS-20 towed body satisfies the requirements of three platforms through common hardware, software and interfaces; common integrated logistics support; and modular operational configurations. The AN/AQS-20 has been extensively tested and operated from unmanned, underwater vehicles such as the AN/WLD-1 and was the only minehunting sonar sensor developed, tested and certified for Remote Multi Mission Vehicle deployment. It is the most advanced and capable mine warfare sensor system, fully integrated with and effectively operated from the Littoral Combat Ship 2.

Operational Modes

The combination of sidescan, forward-looking and gapfiller sonars enables the AN/AQS-20 to detect and classify mine-like objects from the seafloor to the near surface in a single pass. The system also has an electro-optics identification capability that delivers high-definition images of bottom mines using Streak Tube Imaging Laser technology. This provides the operator with both range and contrast data for post-mission analysis to aid in mine identification.

Four modes of operation are provided:

  • Single Pass Shallow Mode — Bottom and moored mine coverage in a single pass
  • Single Pass Deep Mode — Moored mine coverage in deep water
  • Volume Mine Mode — Volume mine coverage at four times the area search rate
  • Identification Mode — Bottom and moored mine coverage in a single pass plus optical imaging of bottom mines

These modes enable the AN/AQS-20 to give timely and accurate information on the location and position of mines to support neutralization by systems such as the Airborne Mine Neutralization System.