Ray Patten, who leads the system development effort at the laboratory, says that the capability would be based on a laser—a "short-pulse optical augmentation system," as he refers to it—fitted to an LCAC or other landing craft, such as the new advanced amphibious assault vehicle (AAAV).
The system would scan the shoreline, much the same way as do radars, from distances beyond the range of enemy weapons. Any laser beam would be reflected as backscatter from grass, trees, and other natural phenomena, but as individual bright spots from the lenses of electro-optical surveillance devices, including targeting systems used by crew-served weapons and armored vehicles.
Such a system, he says, could be used to locate enemy positions and enable the Marines on board the landing craft to call in counterfire before becoming exposed to the enemy's weapons. Unlike infrared systems, the laser would permit the users to determine range as well as azimuth and elevation data, permitting precise calculations of the location of enemy electro-optical surveillance systems.
The Naval Research Laboratory supported by the Maryland Advanced Development Laboratory (MADL), assembled a demonstration system last summer consisting of a short-pulse continuum powerlite laser, a gimballed mirror (needed to direct the laser to the target area), a telescope, and an oscilloscope to collect the data. The Maryland laboratory wrote the system-control software, designed to run on a personal computer.
The system was bore-sighted last summer on the rifle range at Fort Meade, Maryland, and following additional calibration, installed on a barge for at-sea testing at NRL's Chesapeake Bay detachment. The Chesapeake Bay tests detected electro-optical targets at ranges of up to five kilometers. NRL then sent the system to England, where it was again sea-tested by the United Kingdom's Defence Evaluation Research Agency with similar impressive results: at a two-meter range, it detected an electro-optical aperture one-quarter inch in diameter.
Patten points out that NRL considers the system safe for viewing with the unaided eye, and meets the standard for compliance with the Treaty on the Use of Unconventional Weapons, but that the system could dazzle and possibly cause eye injury to a viewer using high-powered binoculars or other telescopic devices.
Navy LCACs are scheduled to undergo a service life extension program, managed by builder Textron Marine & Land Systems, that will include the installation of a command-and-control suite intended to support a new mine countermeasures role.
LCACs are expected to be the primary platform for the deployment of a variety of shoreline mine-detection and breaching systems.
These new missions, according to Marine Corps officials, dovetail with Corps' doctrine, but also create a need for a more effective self-defense system for the craft, which until now have primarily hauled vehicles, supplies, and personnel ashore after the landing force had established a logistics beachhead. A self-defense sensor like the NRL laser would be a nice fit for the craft's new role, they say—if the funds are made available to try it.