The U.S. Navy's newest Multifunction Towed Array (MFTA) is the first new surface ship array to be built for the U.S. Navy in 25 years and is configured as a long 3-inch diameter device that can be towed behind surface ships. The recent contract, awarded to Lockheed-Martin for MFTAs, is intended to replace the existing AN/SQR-19 TACTAS array. It provides several enhancements over existing units, including better coverage, better detection capability and better reliability.

This array will be integrated with AN/SQQ-89Av15 systems that are being installed aboard Arleigh Burke Class guided-missile destroyers and aboard Ticonderoga Class missile cruisers as part of their planned upgrades. The new MFTA is also slated for use on DDG-1000 Zumwalt Class destroyers and the Littoral Combat Ship.

The new MFTA will be part of the U.S. Navy's large program to enhance its anti-submarine capabilities that had been virtually neglected since the end of the Cold War.

One of the first areas that required attention is improved detection. That means wider coverage areas, longer baselines, better sonar and other detection systems — and greater use of small unmanned platforms on the surface and underwater. Unlike a ship's main bow-mounted sonar, a MFTA can quickly be refitted to any ship with a minimum of yard work.

In the U.S., towed array systems are made by a number of manufacturers including EDO/ITT, L-3, Lockheed Martin Undersea Systems and the Chesapeake Science Corp. While such arrays are described as "towed,"it can still be helpful for the arrays to have some attached movement capability.

One of the key technical issues faced by towed arrays is the fact that knowing the shape of the array in the water is critical to interpreting its results.

Unfortunately, currents, maneuvers by the towing vessel, and a myriad of other factors can change the array's shape in the water. Self-monitoring via a pinging device and listening clipped along the array — so called because they measure time of flight — is a commonly used approach for calculating an array's shape, and some kind of monitoring approach will continue to be necessary. Having a streamlined node at the end with some maneuvering ability of its own can also be quite helpful.

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