LASH: Littoral Airborne Sensor Hyperspectral. A new antisubmarine warfare search-and-detection technique, usually deployed from aircraft. LASH utilizes the back-scatter of underwater illumination from sunlight, caught via special optical sensors and processed by classified computer software, to locate anomalous color gradations and shapes, even through deep seawater that is murky or dirty.
LIDAR: Light Direction And Ranging. Like radar, but uses laser beams instead of radio waves. Undersea LIDAR uses blue-green lasers, because that color penetrates seawater to the greatest distance.
Multimission platform: A special extra one-hundred-foot-long, three-thousand-ton hull section added to USS Jimmy Carter, the last of the three Seawolf-class nuclear-powered fast-attack subs to be built, commissioned into the U.S. Navy in early 2005. By limiting the pressure-hull diameter within the central portion of the multimission platform to eighteen feet (the “wasp waist”), additional volume for larger weapons, off-board vehicles, and underwater fiber-optic cable tapping equipment was created between the wasp waist and the outer hull, called the “garage space.” The full-width (forty-two-foot outside diameter) sections at both ends of the multimission platform include areas for special operations command, control, and communications, and for special operations forces berthing — nominally fifty commandos, though more can be accommodated in an emergency. Reportedly, this extra hundred feet of “wetted area” of the outer hull reduces Carter’s maximum speed while submerged by less than one knot.
Naval Submarine League (NSL): A professional association for submariners and submarine supporters. See their Web site, www.navalsubleague.com.
Network-centric warfare: A new approach to warfighting in which all formations and commanders share a common tactical and strategic picture through real-time digital data links. Every platform or node, such as a ship, aircraft, submarine, Marine Corps or Army squad, or SEAL team, gathers and shares information on friendly and enemy locations and movements. Weapons, such as a cruise missile, might be fired by one platform, and redirected in flight toward a fleeting target of opportunity by another platform, using information relayed by yet other platforms — including unmanned reconnaissance drones. Network-centric warfare promises to revolutionize command, control, communications, and intelligence, and greatly leverage the combat power of all friendly units while minimizing collateral damage.
Ocean rover: Any one of a number of designs, either civilian or military, of a small, semiautonomous unmanned submersible vehicle that roves through the ocean collecting data on natural and man-made phenomena. This data is periodically downloaded via radio when the ocean rover comes shallow enough to raise an antenna above the sea surface. Ocean rovers can also be controlled and downloaded via fiber-optic tether from a submerged submarine, for greater stealth. Powered by batteries or fuel cells, ocean rovers move slowly but can have endurance of days or weeks before needing to be recovered for maintenance, reprogramming, refueling, etc. One U.S. Navy ocean rover is the Seahorse series, shaped like a very long, very wide torpedo.
Photonics mast: The modern replacement for the traditional optical periscope. One of the first was installed in USS Virginia (see below). The photonics mast uses electronic imaging sensors, sends the data via thin electrical or fiber-optic cables, and displays the output on large high-definition TV screens in the control room. The photonics mast is “non-hull-penetrating,” an important advantage over older scopes with their long, straight, thick tubes that must be able to move up and down and rotate.
Pump-jet: A main propulsor for nuclear submarines that replaces the traditional screw propeller. A pump-jet is a system of stator and rotor turbine blades within a cowling. (The rotors are turned by the main propulsion shaft, the same way the screw propeller’s shaft would be turned.) Good pump-jet designs are quieter and more efficient than screw propellers, producing less cavitation noise and less wake turbulence.
SERT: Seabee Engineer Reconnaissance Team. A modern breed of special operations forces “shadow warrior” drawn from among U.S. Navy Seabee (mobile construction) combat battalions. SERT teams, generally of ten specially trained men each, operate at the forward edge of the battle area, sometimes attached to Marine Corps formations. They use their special expertise to assess, in a warfighting environment, civil engineering requirements for tasks such as road-laying, bridge repair, and restoration of damaged or sabotaged structures and heavy machinery including power plants and waterworks. Their reconnaissance reports are relayed in real time to higher headquarters via digital network-centric warfare techniques (see above), for optimal rapid exploitation by follow-on mainline battle formations, aid relief workers, and democracy-building planners. Commissioned officers in Seabee units are members of the Navy’s Civil Engineer Corps.
Sonobuoy: A small active (“pinging”) or passive (listening-only) sonar detector, usually dropped in patterns (clusters) from an aircraft or a helicopter. The sonobuoys transmit their data to the aircraft by a radio link. The aircraft might have onboard equipment to analyze this data, or it might relay the data to a surface warship for detailed analysis. (The aircraft will also carry torpedoes or depth charges, to be able to attack any enemy submarines that its sonobuoys detect.) Some types of sonobuoy are able to operate down to a depth of 16,000 feet.
SSBN and SSGN: An SSGN is a type of nuclear submarine designed or adapted for the primary purpose of launching cruise missiles, which tend to follow a level flight path through the air to their target. An SSGN is distinct from an SSBN “boomer,” which launches strategic (hydrogen bomb) ballistic missiles, following a very high lobbing trajectory that leaves and then reenters earth’s atmosphere. Because cruise missiles tend to be smaller than ballistic missiles, an SSGN is able to carry a larger number of separate missiles than an SSBN of the same overall size. Note, however, that since ballistic missiles are typically “MIRVed,” i.e., equipped with multiple independently targeted reentry vehicles, the total number of warheads on an SSBN and SSGN may be comparable; also, an SSBN’s ballistic missiles can be equipped with high-explosive warheads instead of nuclear warheads. (A fast-attack submarine, or SSN, can be thought of as serving as a part-time SSGN, to the extent that some SSN classes have vertical launching systems for cruise missiles, and/or are able to fire cruise missiles through their torpedo tubes.)
Virginia-class: The latest class of nuclear-propelled fast-attack submarines (SSNs) being constructed for the U.S. Navy, to follow the Seawolf-class. The first, USS Virginia, was commissioned in 2004. (Post — Cold War, some SSNs have been named for states, since construction of Ohio-class Trident missile “boomers” has been halted.)
Wide-aperture array: A sonar system introduced, in the U.S. Navy, with USS Seawolf in the mid-1990s, and also built into the Virginia class. Distinct from and in addition to the bow sphere, towed arrays, and forward hull array of Cold War — era Los Angeles—class SSNs. Each submarine so equipped actually has two wide-aperture arrays, one along each side of the hull. Each array consists of three separate rectangular hydrophone complexes. Powerful signal processing algorithms allow sophisticated analysis of incoming passive sonar data. This includes instant ranging (see above). Some Los Angeles—class vessels have been updated with retrofitted wide-aperture arrays.