12 June 2012 Compact optical system for imaging underwater and through the air/sea interface
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Proceedings Volume 8372, Ocean Sensing and Monitoring IV; 837203 (2012); doi: 10.1117/12.918623
Event: SPIE Defense, Security, and Sensing, 2012, Baltimore, Maryland, United States
Typical line-of-sight (LOS)/monostatic optical imaging systems include a laser source and receiver that are co-located on the same platform. The performance of such systems is deteriorated in turbid ocean water due to the large amount of light that is scattered on the path to and from an object of interest. Imagery collected with the LOS/monostatic system through the air/sea interface is also distorted due to wave focusing/defocusing effects. The approach of this project is to investigate an alternate, non-line-of-sight (NLOS)/bistatic approach that offers some advantages over these traditional LOS/monostatic imaging techniques. In this NLOS system the laser and receiver are located on separate platforms with the laser located closer to the object of interest. As the laser sequentially scans the underwater object, a time-varying intensity signal corresponding to reflectivity changes in the object is detected by the distant receiver. A modulated laser illuminator is used to communicate information about the scan to the distant receiver so it can recreate the image with the collected scattered light. This NLOS/bistatic configuration also enables one to view an underwater target through the air-sea interface (transmitter below the surface and receiver above the surface) without the distortions experienced with the LOS/monostatic sensor. In this paper, we will review the results of recent laboratory water tank experiments where an underwater object was imaged with the receiver both below and above the sea surface.
© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Derek Alley, Linda Mullen, Alan Laux, "Compact optical system for imaging underwater and through the air/sea interface", Proc. SPIE 8372, Ocean Sensing and Monitoring IV, 837203 (12 June 2012); doi: 10.1117/12.918623; https://doi.org/10.1117/12.918623



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