The AN/SQQ-32 minehunting sonar set (MSS) is a variable-depth mine-hunting sonar system originally developed by Raytheon and Thales Underwater Systems (formerly Thomson Marconi Sonar) for the United States Navy. [1] It includes two separate active sonar systems to detect and classify mine-like objects on the surface, in the volume, or on the bottom of the sea. The sonar systems are packaged in a single towed body tethered to the ship through a cable providing power and data transmission, with the cable length variable via an electric winch. A hole in the ship extending from the sonar maintenance room (SMR) to the hull allows movement of the towed body in different configurations for maintenance, stowage at sea, and minehunting operations. The towed body can be configured for minehunting by either locking to the bottom of the ship's hull for shallow water operations, or by extending and retracting the tow cable to allow for variable depth sonar (VDS) operations. VDS operations are necessary in deep water due to refraction of the sonar from the various temperature layers present in the ocean; with the sonar positioned in the same thermal layer as the suspected mines the error induced by refraction is minimized. The detect and classify sonar subsystems are independently monitored and controlled by two operators at independent panels working together to find and characterize underwater objects as mine or non-mine like objects.
The SQQ-32 system became operational in 1990 and is currently installed on all mine countermeasures ships in the Avenger class and was previously installed on the Osprey class before decommissioned.
The detect system is a low frequency, low resolution, high range sonar designed to provide a general location of possible mine-like objects. It provides much greater range than the classify sonar system but provides little resolution and detail of the objects it detects. It provides the operator 180 degrees of selectable coverage via electronic switching of sonar stave arrays circling the towed body. The newest AN/SQQ-32(V)4 upgrade contracted in 2011 includes a high frequency wide band (HFWB) modification that greatly improves shallow-water minehunting capabilities in high clutter environments. [2]
The classify sonar has a lower range, but higher frequency and higher resolution to allow the classification of a target as mine-like or non mine-like. Once a target is located by the detect operator, they will hand off the position to the classify operator where they will analyze the characteristics of the object to make a determination if it has mine-like properties. Characteristics include approximate size and shape measurements, ringing patterns caused by metallic objects, and aspect changes as the ship and towed body circle the target.
The AN/SQQ-32(V)4 system upgrade was designed and tested by Naval Surface Warfare Center Panama City and The University of Texas Applied Research Laboratory, and contracted to BAE systems for installation. The initial contract was for installation on four MCM-1 Avenger class minesweepers for $14 million, [3] and later an available option was awarded to upgrade an additional ten units plus a battle spare. [2]
Sonar is a technique that uses sound propagation to navigate, measure distances (ranging), communicate with or detect objects on or under the surface of the water, such as other vessels.
A littoral combat ship (LCS) is either of two classes of relatively small surface vessels designed for near-shore operations by the United States Navy. It was "envisioned to be a networked, agile, stealthy surface combatant capable of defeating anti-access and asymmetric threats in the littorals", although their ability to perform these missions in practice has been called into question.
A minehunter is a naval vessel that seeks, detects, and destroys individual naval mines. Minesweepers, on the other hand, clear mined areas as a whole, without prior detection of mines. A vessel that combines both of these roles is known as a mine countermeasures vessel (MCMV).
The AN/SLQ-25 Nixie and its variants are towed torpedo decoys used on US and allied warships. It consists of a towed decoy device (TB-14A) and a shipboard signal generator. The Nixie is capable of defeating wake-homing, acousting-homing, and wire-guided torpedoes. The decoy emits signals to draw a torpedo away from its intended target.
The Osprey class are a series of coastal minehunters designed to find, classify, and destroy moored and bottom naval mines from vital waterways.
A mine countermeasures vessel or MCMV is a type of naval ship designed for the location of and destruction of naval mines which combines the role of a minesweeper and minehunter in one hull. The term MCMV is also applied collectively to minehunters and minesweepers.
The Tripartite class is a class of minehunters developed from an agreement between the navies of Belgium, France and the Netherlands. A total of 35 ships were constructed for the three navies. The class was constructed in the 1980s–1990s in all three countries, using a mix of minehunting, electrical and propulsion systems from the three member nations. In France, where they are known as the Éridan class they are primarily used as minehunters, but have been used for minesweeping and ammunition transport in Belgium and the Netherlands, where the Tripartites are known as the Alkmaar class.
The AQS-20A is a sonar mine countermeasure detection system, developed by Raytheon. The system was initially tested for use on the MH-60S and MH-53E helicopters and as part of the mission package for the littoral combat ships (LCS) and some United States Navy destroyers of the Arleigh Burke class. However, the Chief of Naval Operations excluded the system from use on helicopter assets in March 2012, and only one destroyer has been outfitted with the specific mission package as of April 2009. The AN/AQS-20 naval mine hunting sonar systems will be employed for deeper mine threats. The "Q-20", as it is commonly called, is an underwater towed body containing a high resolution, side-looking, multi-beam sonar system used for minehunting along the ocean bottom. This rapidly deployable system provides real-time sonar images to operators to locate, classify, mark and record mine-like objects and underwater terrain features. The AQS-20 has an active, stabilized underwater vehicle, equipped with advanced multiple-beam side-looking sonar. The underwater body is towed via a small-diameter electromechanical cable, while an operator can view the underwater image and identify objects on a video monitor while recording the data on S-VHS digital tapes for post mission analysis. Operators actually "fly" the device underwater, controlling the depth of the device the same way that an airplane controls its altitude. Once located, the exact coordinates of mine-like objects can be used by explosive ordnance disposal (EOD) personnel to reacquire and neutralize the mine.
USS Defender (MCM-2) was an Avenger-class mine countermeasures ship in the service of the United States Navy. She entered service in September 1989 and was decommissioned in October 2014.
Geophysical MASINT is a branch of Measurement and Signature Intelligence (MASINT) that involves phenomena transmitted through the earth and manmade structures including emitted or reflected sounds, pressure waves, vibrations, and magnetic field or ionosphere disturbances.
The Landsortclass mine countermeasures vessel were built by Swedish shipbuilding company, Kockums for the Swedish Navy and the Republic of Singapore Navy (RSN) between 1983 and 1996.
Avenger-class mine countermeasures ships are a class of 14 ships constructed for the United States Navy from 1987 to 1994, designed to clear mines from vital waterways. The ships have the hull designator MCM.
The fourth USS Scout (MCM-8) is an Avenger-class mine countermeasures ship of the United States Navy.
The Bedok class are mine countermeasures vessels of the Republic of Singapore Navy (RSN). They play an important role in the maritime security of Singapore, ensuring that the Singapore Strait and the sea lanes surrounding Singapore remain mine-free and open to international shipping. It is estimated that closure of Singapore's ports would result in direct trade losses amounting to more than US$1.2 billion daily, posing a serious threat to Singapore's economy. The four ships form the Sixth Flotilla of the RSN.
USS Warrior (MCM-10) is an Avenger-class mine countermeasures ship of the United States Navy.
The Lerici class is a class of minehunters constructed by Intermarine SpA and owned and operated by the Italian Navy. The class incorporates two subclasses: the first four ships are referred to specifically as the first series of the Lerici class, while eight more ships produced to a slightly modified design are known as "second series Lericis" or as the Gaeta class.
The Koster class is a class of five mine-countermeasure vessels currently in use by the Swedish Navy. Built between 1982 and 1993 as part of the seven-strong Landsort-class mine countermeasures vessels, the last five ships of the class were given a comprehensive midlife upgrade between 2007 and 2010, which resulted in HMS Koster becoming the lead ship of the newly upgraded class of MCMVs. After the upgrade, the Swedish Navy expects that it will serve for another 15 to 20 years. An identifying feature of the Koster class is the fire control radar on top of the bridge.
The Fleet-class unmanned surface vessel, also called the Common Unmanned Surface Vessel (CUSV) and later the Mine Countermeasures Unmanned Surface Vehicle, is an unmanned surface vessel designed for the United States Navy to be deployed from Freedom and Independence-class littoral combat ships and intended to conduct mine and anti-submarine warfare missions. As of 2012 four units of the class have been built; the first was delivered to the U.S. Navy in 2008.
The Knifefish is an autonomous unmanned underwater vehicle (UUV) under development by General Dynamics Mission Systems and Bluefin Robotics for the United States Navy. It is a propeller-driven minesweeping robot designed to replace the Navy's trained dolphins and sea lions after the retirement of the 50-year-old Marine Mammal Program in 2017. The Knifefish was first unveiled at a Navy exposition in April 2012, and was originally intended to operate in concert with the Navy's littoral combat ships (LCS) as part of a specialized counter-mine system.
The AN/SQS-504 Diver was an early naval medium-frequency active variable depth sonar (VDS) developed in Canada.