Differential Absorption Lidar (DIAL) Measurements of Atmospheric Water Vapor Utilizing Robotic Aircraft

A new unpiloted air vehicle (UAV) based water vapor DIAL system will be described. This system is expected to offer lower operating costs, longer test duration and severe weather capabilities. A new high-efficiency, compact, light weight, diode-pumped, tunable Cr:LiSAF laser will be developed to meet the UAV payload weight and size limitations and its constraints in cooling capacity, physical size and payload. Similarly, a new receiver system using a single mirror telescope and an avalanche photo diode (APD) will be developed. Projected UAV parameters are expected to allow operation at altitudes up to 20 km, endurance of 24 hrs and speed of 400 km/hr. At these conditions measurements of water vapor at an uncertainty of 2-10% with a vertical resolution of 200 m and horizontal resolution of 10 km will be possible.