Mine-locating lidar system delivered to US Navy

The first two Magic Lantern lidar-based systems for locating moored and floating mines have been delivered to the US Naval Reserve Helicopter Squadron, which will deploy them as needed on Navy destroyers beginning this year. The pod-mounted system was developed by Kaman Aerospace (Bloomfield, CT) for use on the SH-2G Super Seasprite helicopters made by the company.

Rick DeMeis

Feb. 1, 1997

2 min read

The mine-location system is based on a frequency-doubled Nd:YAG laser that produces 20 W of 532-nm output; the laser was developed by Fibertek (Herndon, VA; see figure). According to the Navy, to detect mines “from the surface down to a keel depth greater than that of any US warship,” target returns from laser pulses scanned below the helicopter are detected by six intensified charge-coupled-device cameras with variable shutter timing. The timing delays allow for range gating to gauge the depth location of imaged mines.

Pod-mounted Magic Lantern mine-location system uses range gating of repeatedly scanned laser pulses with an intensified CCD camera system to determine mine depth as well as surface coordinates while minimizing false-target indications.

Multiple scans allow reliability in detection with a low false-alarm rate. Phillip Lacovara, director of business development at the Kaman Electro-optics Development Center (Tucson, AZ), where the cameras are manufactured, notes that the maturing of the technology over the last decade was the result of “building a little and testing a lot, for both hardware and software.”

The helicopter is equipped with a display station that presents camera images to an operator in real time. Also part of the system is a Global Positioning System navigation receiver that correlates imager data for precise target location. These data then allow the mines to be cleared or avoided by ships.

Further development

Kaman currently has a $6.5 million contract to fabricate another Magic Lantern pod. The company will modify five other squadron aircraft to carry the system, in addition to the one helicopter completed thus far, under a separate $1 million program. The system is designed to allow the pod to be installed on a helicopter in about four hours and has numerous built-in test functions.

Moored and floating mines are the most numerous kinds of antiship mines in the world and pose threats to shipping in such areas as the Arabian Gulf. Navy airborne-mine-countermeasures director Capt. Bill Arnold says, “Since 1950, 14 Navy ships have been lost or seriously damaged by mines, which is more than all other causes of loss or damage combined.”