Navy orders 126,000 air-launched sonobuoys to detect underwater sounds in anti-submarine warfare (ASW)
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 $181.9 million order Wednesday to ERAPSCO in Columbia City, Ind., for 126,000 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.
This order is for 100,000 AN/SSQ-53, 16,000 AN/SSQ-101, and 10,000 AN/SSQ-62 production sonobuoys for annual training, peacetime operations, and testing.
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.
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-53F directional frequency and ranging (DIFAR) sonobuoy, which is dropped from fixed-wing aircraft or helicopters, 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.
Each AN/SSQ-53F sonobuoy is designed to determine the direction from which it can hear submarine noises, so a pattern of sonobuoys can determine a submarine contact's range, bearing, and location by using triangulation.
The Navy Boeing P-8A Poseidon maritime patrol jet will be able to drop sonobuoys from relatively high altitudes on large-area patterns. The aircraft will be able to monitor signals from sonobuoy fields, or hand off that job to the Navy MQ-4C Triton broad-area maritime surveillance unmanned aerial vehicle (UAV).
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.
The AN/SSQ-101B is a NATO A-size sonobuoy that has a commandable passive search capability. When deployed, the ADAR array uses a pentagon shaped, horizontally oriented pattern of hydrophones to detect and beam form underwater sound waves. All of the 40 hydrophones are located along the circumference and radials of the array structure.
The sonobuoy converts its analog output of each hydrophone to a digital signal that is serialized, beam formed, and sent to the surface transceiver that transmits on a 5-Watt minimum FSK modulated radio link.
This sonobuoy features electronic function select (EFS) for use prior to load and launch. A UHF command downlink enables the operator to modify the sonobuoy’s mode of operation after it has been deployed in the water with the sonobuoy's command function select (CFS).
The AN/SSQ-101B from helicopters, fixed-wing aircraft, or from the deck of a surface vessel. When air deployed, the sonobuoy's descent is stabilized and slowed by a parachute.
Long term, Navy officials are concerned that the AN/SSQ-101 sonobuoy does not provide enough array gain in some important operational areas. As a result, the Navy is working with industry to develop a new volumetric acoustic receive array with a large horizontal and vertical aperture for use with the extended echo ranging (EER) family of active ASW search systems.
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.
The AN/SSQ-62 sonobuoys work together with the Navy's AN/SSQ series of sonobuoys, which in addition to the AN/SQQ-62 consist of the SSQ-36 bathythermograph (BT); SSQ-53 passive directional low frequency analyze and record (DIFAR); SSQ-101 air deployed active receiver (ADAR); SSQ-110 multi-static non-coherent source; and SSQ-125 multi-static coherent source.
The AN/SSQ-62E is a fifth-generation all-digital sonobuoy for detecting and localizing submarines in preparation for attack. It provides range and bearing to the target for accurate position fixing.
Unlike previous versions, any AN/SSQ-62E sonobuoy supports any of the four acoustic frequencies as selected via the electronic function select.
The AN/SSQ-62E also incorporates command function select, which enables the operator to modify the sonobuoy’s mode of operation even after it has been deployed. The AN/SSQ-62E uses a standard lithium sulphur dioxide battery pack.
The AN/SSQ-62E DICASS is air launchable from fixed-wing aircraft and helicopters. Descent of the sonobuoy from the air is stabilized and slowed by a parachute. It also is deployable from the deck of a surface vessel.
The AN/SSQ-62E offers an all-digital design; is commandable to different depths, operational duration, and scuttle; has a high-power 96-channel RF transmitter; can be commanded to different RF channels, additional depths, and sonic frequency; is compatible with known airborne acoustic processors; and is factory-configurable to AN/SSQ-62D or 62B standards.
The AN/SSQ-62E weighs 35 pounds; has one Watt minimum RF transmitter operating frequency; is 96 Channel selectable to frequencies between 136 and 173.5 MHz; operates for at least one hour; operates at depths of 90, 400, or 1500 feet; has a piezoelectric ceramic omnidirectional transmit and receive sonar transducer; and has a shelf life of five years in a sealed container.
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 order in De Leon Spring, Fla., and Columbia City, Ind., and should be finished by September 2025. For more information contact ERAPSCO online at www.erapsco.com, Sparton Defense & Security at www.sparton.com, Ultra Maritime at www.ultra.group/us/our-business-units/maritime, or Naval Air Systems Command at Paste link here.
John Keller | Editor-in-Chief
John Keller is the Editor-in-Chief, Military & Aerospace Electronics Magazine--provides extensive coverage and analysis of enabling electronics and optoelectronic technologies in military, space and commercial aviation applications. John has been a member of the Military & Aerospace Electronics staff since 1989 and chief editor since 1995.
