Ocean Vertical Column Optical Sound Velocity Profiler

Physical Sciences Inc. (PSI) proposes to develop an underwater optical sensor for spatially continuous measurement of sound velocity profiles. The sensor leverages multiple technological advances, including a light detection and ranging (LIDAR) technique applicable for depth-resolved measurements over a large range of water columns, Raman scattering spectroscopy for remote sensing of water temperature and salinity, and a computational spectroscopy approach for high efficiency, time-resolved spectroscopic measurements. During the Phase I program, PSI developed a sensor prototype and demonstrated the technology measurement feasibility during laboratory and field tests. The Phase I data indicated that the Raman scattering signals returned from water are sufficient to support accurate LIDAR measurement of water temperature and salinity, consistent with literature reports. The Phase I work further demonstrated the feasibility of remote measurement of these water parameters based on a LIDAR Raman setup - a critical step towards the goal of spatially continuous quantification of ocean sound velocity. During the Phase II, PSI will continue the technology development and demonstrate the capability of a senor unit within a UUV compatible package. The Phase II sensor will be integrated into a commercial UUV and tested under representative in-water conditions for a final performance demonstration.