A scanned laser and tracking system for sea floor profiling and precision survey

A feasibility study for a scanned laser to generate a contour map of the sea floor has been completed. Analysis and experimental test results indicate improved horizontal resolution compared to side scan sonar for ranges to approximately 90 meters in clear water (
\alpha\leq .05 m^{-1}
) and vertical accuracy to 0.75%. The configuration studied performs best in a side-to-side scan below the vehicle and, therefore, can "fill the gap" for side scan sonar. The Scanned Laser and Tracking System, SLATS, employs a blue-green laser which scans mechanically in a lateral direction about the nadir. Reflected light from the sea floor is sensed by an integrating image tube which is located a fixed distance from the laser. This receiver registers the location of the laser as the beam sweeps the scene, with range to the sea floor determined by triangulation. Lateral scan of the laser provides one dimension of a raster while forward motion produces the second.