Light Weight Coastal Topographic/ Bathymetric Charting System for Naval Unmanned Airborne Vehicles

Sigma has developed a highly successful, airborne, 100 beam, photon-counting, 3D imaging lidar which operates at a laser repetition rate of 22 Khz and is therefore capable of an unprecedented 2.2 Megapixel per second data rate in topographic mode. The system uses a single passively Q-switched microchip laser operating at 532 nm (near the transmission peak of water) and was designed to fit into the nose cone of an Aerostar mini-UAV. It has successfully performed high resolution (15 cm horizontal, 6 cm vertical) surface topography over wide swaths (up to 524 m) from a nominal operating altitude of 1 km. The mass and weight of the Sigma lidar is roughly an order of magnitude less than the operational SHOALS-3000 lidar We propose to modify the lidar design to provide (in addition to the current topographic mode) one or more software-selectable hydrographic modes of operation, permitting trades between depth penetration and horizontal spatial resolution during bathymetry operations. The active lidar will also be mated with an optically coregistered passive hyperspectral camera which best duplicates the performance of the operational CASI-1500 and the final package will be configured to fit in one of the larger Naval Tier II UAVs, the RQ-Pioneer.