AN/SQQ-89

The AN/SQQ-89 is a highly advanced surface ship Undersea Warfare (USW) combat system that plays a central role in the U.S. Navy’s ability to detect, track, and engage submarines and torpedoes. It combines multiple acoustic sensors, including hull-mounted sonar, tactical towed arrays, and sonobuoys, into a single integrated system that provides operators with a comprehensive picture of the undersea battlespace. By fusing data from these diverse sources, the system ensures that naval forces can maintain superiority in both open-ocean and littoral environments where submarine threats are increasingly sophisticated.

At the heart of the system is the AN/SQS-53 hull-mounted sonar, which provides both active and passive detection capabilities. This sonar is designed to transmit powerful acoustic signals into the water and then analyze the returning echoes to identify potential submarine contacts. In passive mode, it listens for the unique acoustic signatures of submarines and torpedoes, allowing ships to detect threats without revealing their own position.

Complementing the hull-mounted sonar is the AN/SQR-19(V) tactical towed array sonar, which extends the ship’s detection range significantly. This long, flexible array is deployed behind the vessel to reduce self-noise interference and to capture faint acoustic signals from distant submarines. Its ability to perform acoustic intercept functions also allows it to detect and classify hostile sonar emissions, giving the ship an early warning of potential threats.

The system also integrates the use of sonobuoys, which can be deployed by helicopters or directly from the ship to expand the surveillance area. These expendable sensors provide additional coverage in regions where the ship’s hull-mounted or towed sonar may have limitations, such as shallow waters or areas with complex acoustic conditions. By networking sonobuoy data with shipboard sensors, the AN/SQQ-89 creates a layered detection capability that is both flexible and resilient.

One of the defining strengths of the AN/SQQ-89 is its integrated processing capability, which combines active and passive acoustic energy into a unified operational picture. Advanced algorithms process the incoming data, filter out background noise, and highlight potential contacts for operators to evaluate. This fusion of information reduces the cognitive load on personnel and increases the speed and accuracy of threat detection and classification.

Weapon control integration is another critical feature of the system, linking the acoustic sensors directly with the ship’s Combat Direction System (CDS). Once a submarine or torpedo has been detected and classified, the system can provide targeting data to anti-submarine weapons such as torpedoes or rocket-assisted projectiles. This seamless connection between detection and engagement ensures that the ship can respond rapidly to undersea threats.

To support the training and readiness of naval personnel, the AN/SQQ-89 includes an onboard training capability. This feature allows operators to practice using the system in simulated scenarios that replicate the acoustic conditions of real-world environments. By training directly on the operational equipment, crews can build confidence and proficiency without the need for live exercises, which are costly and time-consuming.

The system’s key components work together to create a robust and adaptable undersea warfare capability. The AN/SQS-53 hull-mounted sonar provides the primary detection function, while the AN/SQR-19(V) towed array extends the ship’s reach and sensitivity. The AN/SQQ-28(V) LAMPS MK III integrates shipboard electronics with airborne platforms, enabling coordinated anti-submarine operations between surface ships and helicopters. The ASWCS MK 116 serves as the control system that ties these elements together, ensuring smooth coordination and efficient execution of anti-submarine warfare missions.

A major advantage of the AN/SQQ-89 is its open architecture design, which allows for continuous upgrades and integration of new technologies. This modular approach ensures that the system can evolve to meet emerging threats without requiring complete replacement. By adopting commercial off-the-shelf components and standardized interfaces, the Navy can incorporate innovations more quickly and at lower cost.

The system undergoes regular modernization through a process known as Technical Insertions (TI), which includes biannual software upgrades and periodic hardware refreshes. These upgrades, known as Advanced Capability Builds (ACBs), introduce new algorithms, improved displays, and enhanced data processing techniques. Every four years, hardware upgrades are implemented to ensure that the system remains compatible with the latest technologies and maintains peak performance.

Modernization efforts have increasingly focused on improving contact fusion, which is the ability to combine data from multiple sensors into a single, coherent track. This capability is essential in complex acoustic environments where false contacts and background noise can obscure real threats. By refining data processing and classification methods, the AN/SQQ-89 enhances the accuracy of submarine detection and reduces the risk of misidentification.

The system’s adaptability makes it particularly valuable in littoral regions, where shallow waters, variable salinity, and high levels of background noise present unique challenges. Traditional deep-water sonar systems often struggle in these environments, but the AN/SQQ-89’s combination of hull-mounted sonar, towed arrays, and sonobuoys provides a flexible toolkit for operators. This versatility ensures that U.S. Navy ships can operate effectively in any theater of operations, from the open ocean to coastal waters.