Lower tropospheric water vapor measurements are performed at nighttime using the mobile atmosphere monitoring lidar-2 (AML-2) which is operated by the Anhui Institute of Optics and Fine Mechanics. In this lidar system, a 354.7-nm light from a Nd:YAG laser is used as stimulating source, whose Raman shifted center wavelengths are at 386.7 and 407.5 nm for nitrogen and water vapor, respectively. We present a novel and convenient method for determining the Raman lidar calibration constant according
