Laser applications in the littoral: search lidar and ship identification

Naval operations in the littoral have to deal with the threat of small sea-surface targets. These targets have a low radar cross-section and low velocity, which makes them hard to detect by radar in the presence of sea clutter. Search lidars can provide an alternative detection capability for small sea-surface targets at ranges up to 10 km (using commercially available parts). The lidar clutter is much smaller than the radar clutter due to the smoothness of the sea surface for optical wavelengths, thus almost all laser light is scattered away from the receiver. By using a high rep-rate laser the search time is limited in order to be useful in the operational context of coastal surveillance and naval surface surveillance. In the same scenario, a laser range profiler with a high bandwidth, fast laser receiver can be used to for identification of the various contacts. To this end, the experimental results have to be compared to a database with premeasured or pre-calculated range profiles of possible targets. The good match between experimental and simulated laser range profiles implies that such a database can be constructed from 3D-target models, thus simplifying the database creation.