Navy makes big purchase of multistatic sonobuoys for anti-submarine warfare (ASW) against advanced threats

March 9, 2021
The AN/SSQ-125 sonobuoy can generate a variety of waveforms, and is designed to work with the AN/SSQ-53F, AN/SSQ-77C, and AN/SSQ-101 (ADAR) sonobuoys.

PATUXENT RIVER NAS, Md. – U.S. Navy anti-submarine warfare (ASW) experts are replenishing their supplies of advanced multistatic air-launched sub-hunting sonobuoys that work together with other sonobuoys to detect, pinpoint, and track enemy submarines.

Officials of the Naval Air Systems Command at Patuxent River Naval Air Station, Md., announced a $71.3 million order Wednesday to ERAPSCO in Columbia City, Ind., for as many as 20,000 AN/SSQ-125 multistatic sonobuoys for airborne ASW operations.

Sonobuoys are air launched expendable, electro-mechanical ASW acoustic sensors designed to relay underwater sounds of ships and submarines. Sonobuoys enable Navy ASW forces to track potentially hostile submarines operating in the open ocean and in coastal areas that could be threats to Navy carrier battle groups or other forces. Information from these systems can help enable precision attacks with air-launched torpedoes.

Navy fixed-wing aircraft and helicopters can drop a pattern of sonobuoys, which relay information back to the aircraft by radio link, to determine the exact locations of enemy submarines.

Related: Navy makes big order of anti-submarine warfare (ASW) sonobuoys to help aircraft find enemy subs

The AN/SSQ-125 sonobuoys work together with the Navy's AN/SSQ series of sonobuoys, which consist of the SSQ-36 bathythermograph (BT); SSQ-53 passive directional low frequency analyze and record (DIFAR); SSQ-62 directional command active sonobuoy system (DICASS); SSQ-101 air deployed active receiver (ADAR); SSQ-110 multistatic non-coherent source; and SSQ-125 multistatic coherent source.

The AN/SSQ-125 sonobuoy is a source in a multistatic field, and can generate a variety of waveforms, and is designed to work with the AN/SSQ-53F, AN/SSQ-77C, and AN/SSQ-101 (ADAR) sonobuoys.

A multistatic sonar system contains several spatially diverse monostatic or bistatic sonar components with a shared area of coverage, and enable Navy ASW operators to use sensor fusion to combine the power of the separate sonobuoys.

The AN/SSQ-125’s RF channel can be programmed to any of the standard sonobuoy operating channels. At any time after deployment, the AN/SSQ-125 can be commanded to change its operating parameters or depth (deeper only), generate a ping, or scuttle.

Related: Navy places order for 166,500 anti-submarine warfare (ASW) sonobuoys in $219.8 million deal

The AN/SSQ-125 sonobuoy is a source in a multistatic field, and can generate a variety of waveforms, and is designed to work with the AN/SSQ-53F, AN/SSQ-77C, and AN/SSQ-101 (ADAR) sonobuoys.

The AN/SSQ-125’s RF channel can be programmed to any of the standard sonobuoy operating channels. At any time after deployment, the AN/SSQ-125 can be commanded to change its operating parameters or depth (deeper only), generate a ping, or scuttle.

The AN/SSQ-36B provides vertical temperature profiles of the ocean layer for ASW and research, and used widely in ASW operations to evaluate local effects of seawater temperature on sonar propagation and acoustic range prediction.

Related: Signal Systems Corp. to develop enabling technologies for anti-submarine warfare (ASW) airborne sonar

The AN/SSQ-53F uses four hydrophones -- each one a multichannel directional piezoelectric ceramic transducer -- that operate at depths of 90, 200, 400, and 1,000 feet to listen for potentially hostile submerged enemy submarines. Aircraft can drop a pattern of sonobuoys, which relay information back to the aircraft by radio link, to determine the exact locations of enemy submarines.

The SSQ-53F has three sensors: a constant shallow omni (CSO), an advanced DIFAR sensor, and a calibrated wideband omni. The buoy digitally conditions and amplifies the acoustics and provides directional data that helps establish azimuthal bearing to the submarines being tracked.

The AN/SSQ-62E DICASS sonobuoy is for detecting and localizing submarines in preparation for attack. I can provide range and bearing to the target to fix position, and can support any of the four acoustic frequencies as selected via the Electronic Function Select.

Related: Navy orders new supplies of anti-submarine sonobuoys for ocean surveying, tracking, and attack

The AN/SSQ-101 ADAR sonobuoy provides a commandable passive search capability, and functions as the receiver in a multistatic active receiver system. The device uses a pentagon-shaped horizontally oriented pattern of hydrophones to detect and beam form underwater sound waves.

ERAPSCO operates as a joint venture between the Sparton Corp. in Le Leon Springs, Fla., and the Ultra Group Maritime segment in Columbia City, Ind.

The company will do the work on this contract in DeLeon Springs, Fla. and Columbia City, Ind., and should be finished by March 2023. For more information contact ERAPSCO online at www.erapsco.com, Sparton Defense & Security at https://sparton.com, Ultra Maritime www.ultra.group/us/our-business-units/maritime, or Naval Air Systems Command at www.navair.navy.mil.

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