Lidar Atmospheric Sensing Experiment (LASE) Validation

An extensive validation experiment was conducted in September 1995 from Wallops Island, Virginia, to evaluate the performance of the LASE (Lidar Atmospheric Sensing Experiment) system for the measurement of water vapor profiles under a wide range of atmospheric and solar background conditions. During this experiment, the LASE system was flown on a high-altitude (ER-2) aircraft on ten missions for a total of 60 hours. LASE measurements of tropospheric water vapor were compared with in situ measurements from balloons and aircraft that were flown under the ER-2 and with remote measurements from the ground and from aircraft. A high-altitude aircraft (Lear Jet) was equipped with two in situ hygrometers, and a medium to low altitude aircraft (C-130) had onboard the NASA Langley airborne water vapor DIAL system and two in situ hygrometers. Several radiosondes were launched during each LASE flight, and some of these sondes were part of a concurrent international radiosonde intercomparison campaign sponsored by the World Meteorological Organization. The NASA Goddard Scanning Raman lidar also provided nighttime water vapor profile measurements from the ground. During this field experiment, LASE was also used in a number of atmospheric case studies including measurements of Hurricane Luis, a coastal sea breeze development, a strong cold front, an upper level front, and cirrus clouds.