Project ABLE: (Atmospheric Balloonborne Lidar Experiment)

Project ABLE (Atmospheric Balloon Lidar Experiment) is part of the A. F. Geophysics Laboratory's continuing interest in developing techniques for making remote measurements of atmospheric quantities such as density, pressure, temperatures, and wind motions. The system consists of a balloonborne lidar payload designed to measure neutral molecular density as a function of altitude from ground level to 70 km. The lidar provides backscatter data at the doubled and tripled frequencies of a Nd:YAG laser, which will assist in the separation of the molecular and aerosol contributions and subsequent determination of molecular and aerosol contributions and subsequent determination of molecular density vs altitude. The object of this contract was to fabricate and operate in a field test a balloonborne lidar experiment capable of performing nighttime atmospheric density measurements up to 70 km altitude with a resolution of 150 meters. The payload included a frequency-doubled and -tripled Nd:YAG laser with outputs at 355 and 532 nm, a telescoped receiver with PMT detectors, a command- controlled optical pointing system, and support system, including thermal control, telmetry, command, and power. Successful backscatter measurements were made during field operations which included a balloon launch from Roswell, NM and a flight over the White Sands Missile Range. Keywords: Photomultiplier detectors; Lidar; Balloonborne payload; Atmospheric density; Neodymium:YAG laser; Rayleigh scattering; Aerosol Scattering.