Velocimetric Flash LiDAR for Underwater Autonomous Vehicles

Physical Sciences Inc (PSI), in cooperation with the University of Rhode Island (URI), will develop a Velocimetric Flash LiDAR (VFL) for Underwater Autonomous Vehicles (UAV).  The VFL will combine (and extend) two capabilities previously developed and demonstrated at PSI: an underwater flash lidar (UWFL) and an expendable seawater optical attenuation meter (K-meter).  K-meter mode is a high speed, low power mode that supports measurement of seawater optical properties including extinction and the diffuse attenuation coefficient.  This mode can act as a trigger, where a sudden increase in these quantities would be indicative of a scene with increased content (e.g. air bubbles, marine snow or hard targets), warranting further investigation. The system would then transition into UWFL mode, where ranging and imaging information about the scene can be gathered to assess, for example, 3D bubble concentration, presence of white caps, or (with successive measurements) marine snow fall rates.  The resulting data will be processed on board to extract the key pieces of information (e.g. optical property, bubble concentration, marine snow fall rates, etc) to minimize required data transmission bandwidths.  The Phase I program will demonstrate the feasibility of the VFL architecture, specifically focusing on measuring surrogate marine snow fall rates.