A compact water vapor Raman lidar

Continuous monitoring of atmospheric water vapor mixing ratio profiles, especially within the planetary boundary layer is required for weather assessment, global circulation models and atmospheric studies. Although conventional lidar techniques based on Raman scattering or differential absorption are capable of such measurements, they are usually large, expensive systems with high power lasers which pose eye safety problems. This paper describes a compact, cost effective, eye-safe, Raman lidar operating in the solar blind wavelength region that can be used for autonomous daytime and nighttime monitoring of water vapor in the lower atmosphere. The performance of the compact Raman lidar was simulated and also experimentally verified with a bread-board lidar. Daytime measurements of up to 2.5 km and nighttime measurements to over 3 km with 10% accuracy can be obtained with less than 10 minutes of averaging.