Evaluation of a coherent 2-µm differential absorption lidar for water vapor and radial wind velocity measurements

Abstract

The performance of a coherent 2-µm differential absorption lidar (DIAL) for simultaneously measuring water vapor (H ₂O) and radial wind velocity was evaluated. For measuring H ₂O, a wavelength locking technique was applied to the H ₂O-DIAL system. The H ₂O-DIAL system was evaluated under summer daytime conditions in Tokyo, Japan. H ₂O-DIAL measurements were compared with measurements from radiosondes. The H ₂O-DIAL-derived volumetric humidity values agreed with the radiosonde-derived values over the range from 11 to 20 g/m ³ with a correlation coefficient of 0.81 and a root-mean-square difference of 1.46 g/m ³. Comparisons between the H ₂O-DIAL and the in-situ surface meteorological sensors demonstrated the simultaneous measurement of H ₂O and radial wind velocity.