Gated, Underwater Lidar for Lateral Shear and Strain (GULLSS)

Physical Sciences Inc. (PSI), in collaboration with the University of New Hampshire (UNH), will develop a Gated, Underwater LIDAR for Lateral Shear and Strain (GULLSS) measurement system. The proposed technology development addresses the need to measure finescale (1-10m) lateral gradients of ocean velocity for environmental sensing of anisotropic turbulence. The GULLSS system will generate 2D maps of ocean velocities, covering a lateral range of 1-10 m. An optically gated imaging approach will be used, enabling the system to image a thin slice of the water (~1 mm scale) in the lateral plane. A novel, rapidly gated implementation of particle image velocimetry (PIV) will be used to measure velocity gradients within the image plane. This technology provides high flexibility in the trade-space of measurement speed, imaging field of view and resolution, enabling real-time optimization of measurement parameters. The sensor will be deployed either below or above the lateral plane at a large distance (e.g., several meters) without interfering with the flow dynamics. The distance of the image plane from the sensor is adjustable with a precision of < 1 mm. The capability provided by the envisioned GULLSS sensor fulfills the need to measure the finescale lateral flow distribution within lateral planes of water turbulence.