Performance evaluation of coherent 2-μm differential absorption and wind lidar for wind measurement

Abstract

A coherent 2-μm differential absorption and wind lidar (Co2DiaWiL) has been built with a high power Q-switched Tm,Hm:YLF laser to measure CO 2 concentration and radial wind velocity. Our experiment was conducted to test the ability of the Co2DiaWiL to make wind measurement in the atmospheric boundary layer and lower free troposphere. The bias in the velocity measurement was estimated as –0.0069 m/s using measurements from a stationary hard target. The magnitude of the random error of radial velocity measurements was determined from data in the vertical pointing mode and the Co2DiaWiL achieved a velocity precision of 0.12 m/s. The radial velocity measurements to ranges up to 20-25 km by the horizontally fixed beam mode for average times of 1 min have been demonstrated with the high laser output power. The Co2DiaWiL-measured radial velocities were directly compared with the wind speeds measured by a closelylocated sonic anemometer. The correlation coefficient was as large as 0.99 for comparison of radial velocities averaged for 1 min from the Co2DiaWiL and sonic anemometer.