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

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