Ground Testing Of 2-Mu M Triple-Pulse Ipda Lidar For Carbon Dioxide And Water Vapor Measuremets

A triple-pulse, 2-mu m, Integrated Path Differential Absorption (IPDA) lidar was developed at NASA Langley Research Center. This active remote sensing instrument provides a technique for measuring atmospheric carbon dioxide and water vapor simultaneously and independently. A 2-mu m high-energy pulsed laser is incorporated for the IPDA transmitter, which provides high signal-to-noise ratio measurements using a commercial direct detection system. This results in a high-precision measurement capability for the low troposphere weighted-average column dry-air volume mixing ratio of the gases. Recent IPDA ground testing indicated carbon dioxide and water vapor measurements sensitivities of 8% and 14%, respectively and biases of 0.1%. However, using the R30 centerline position for the on-line enhances the CO2 measurement sensitivity to 0.6%.