Navy moves to ladar for minehunting
By John McHale
WILLOW GROVE NAVAL AIR STATION, Pa. - U.S. Navy leaders are entering a new era of undersea warfare with the first fielded use of laser detecting and ranging technology - ladar, for short - to hunt shallow and floating mines at sea.
Engineers from the Navy and Kaman Corp. of Bloomfield, Conn., outfitted an SH-2G Super Seasprite helicopter from Reserve Helicopter-Anti-Submarine Squadron Light 94 (HSL-94) with the Kaman-developed Magic Lantern, the first fielded electro-optic airborne mine countermeasure (AMCM) system.
The $6 million Magic Lantern uses a blue-green laser and camera array to scan the water below the helicopter from the surface down to a keel depth greater than any U.S. aircraft carrier, says Lt. Cmdr. Wade Burchell, HSL-94 public affairs officer. The system correlates multiple scans to identify the mines.
It is the only AMCM system able to sweep at and below the sea surface and the only one cleared for day and night operations, he says.
The small size of the systems enable them to be deployed aboard a wide range of platforms, says Marine Corps Maj. Gen. Edward Hanlon, director of Expeditionary Warfare at the Pentagon. "Magic Lantern gives the squadron the deployment capability to support U.S. Naval forces with AMCM off any air capable ship in the Navy," Burchell adds.
"It has demonstrated a higher probability of detection, lower false alarm rate, and a greater area coverage in looking for and finding contact mines than any system available to the Navy today," Hanlon said during the Magic Lantern roll-out ceremony in December at Willow Grove Naval Air Station, Pa.
The Magic Lantern pod replaces the magnetic anomaly detector on a strengthened hardpoint on the right side of the helicopter. The system display in the aft cabin of the SH-2G shows the sensor operator mine detection symbology and real-time video imagery of suspected mine contacts, according to a Navy statement. The ASN-150 tactical navigation system will provide signals to the horizontal situation indicator in the cockpit enabling the pilots to fly predetermined search patterns.
A Tactical Decision Aid (TDA) helps the three-man SH-2G crews determine search patterns and analyze post-mission data. TDA software runs on a standard computer workstation aboard the ship. The position of mines detected by Magic Lantern can be downloaded by the TDA, for subsequent distribution to other units.
The miniaturized airborne Global Positioning System (GPS) receiver which is a part of the SH-2G modifications, annotates contacts with precise navigation coordinates. With contact positions fixed, the helicopter crew can overfly mine contacts and direct minesweeping aircraft or ships to the location. Mine contacts detected during a mission are stored on a data disk for post-mission review on the TDA.
Advantages of ladar
Ladar is faster, safer, smaller, and more efficient than existing minehunting approaches, Hanlon says. "While other airborne systems are effective at detecting, classifying, and localizing mines, they cannot always cover as much area as operational commanders might require in a given period of time. Airborne electro-optics systems not constrained by the slower speed required to tow some of the fleet`s existing systems, can operate at a considerably higher area coverage rate," Hanlon says.
"The helicopter moves at about 65 knots, and the Magic Lantern has the capability to track mines in a wide scan of 50 square miles," Burchell says. "Comparing the Magic Lantern to previous AMCM systems is like comparing a motorcycle to bicycle."
"Seventy-five percent of damage to U.S. Navy capital ships in the last 10 years was caused by mines, two of which used World War I technology," Hanlon says.
"Floating and moored mines are the most plentiful anti-ship mines in the world and pose the greatest risk to military and commercial ships, especially in areas such as the Arabian Gulf," Burchell says. "Since 1950, 14 navy ships have been lost or seriously damaged by mines, more than all other causes combined."
The precise navigation data from the GPS should help minehunting crews avoid mine-related disasters of the past, and in fact should enable single ships or carrier/amphibious battle groups to avoid them completely, Burchell says.
Magic Lantern deployment
HSL-94 has received two magic lantern systems and will receive a third in December 1997. One SH-2G is assigned to the squadron to carry the minehunting system and will support the deployed systems in the fleet, Burchell says. Standard 17-member detachments with the SH-2G and Magic Lantern will be augmented with a Kaman technical representative.
Plans call for all six HSL-94 Super Seasprites to receive Magic Lantern, he says. The upgrade takes approximately one week. The system has a built-in test capability.
"The Magic Lantern has also been flown aboard the MH53 helicopter, which is used for mine disposal, but has not been tested on the aircraft," Burchell says.
The MH53 is the Navy`s largest helicopter, and when disposing mines moves at 10 to 20 knots cutting the mines with a line from the air, he explains. "However, it cannot dispose and detect mines at the same time, because there is not enough room on the helicopter."
The SH-2G Super Seasprite Helicopter is outfitted with the Kaman-developed Magic Lantern (Inset) AMCM system.
