| Popis: |
This report provides a summary of the second in-water test of the LLNL/NAVSEA Underwater Laser Imaging System (UWLIS). The UWLIS is a laser-based, synchronous-scanning, underwater imaging device that is designed to operate at greater ranges than is possible with conventional underwater TV cameras. It differs from earlier prototype synchronousscanning systems in that it is capable of high scan rates that allow the generation of real-time, RS-170 video images. The UWLIS is being developed for eventual use on Remotely Operated Vehicles (ROVs) during deep-ocean Naval salvage missions. The floodlight-illuminated television cameras presently used on NAVSEA vessels can produce images at ranges up to about 2 attenuation lengths (AL) (2). Beyond that point, common volume backscatter from particulates in the intervening seawater between the imager and the target overwhelms the return signal, and the image is lost. The special optical geometry of the synchronous-scanning imager is designed to minimize common-volume effects. Previous theoretical studies (1) indicate that a system of this type should be capable of operation at distances as great as 6 to 7 attenuation lengths. An improvement of this magnitude would greatly increase the efficiency of salvage operations, thus decreasing their cost. |
