A high-spectral-resolution lidar can measure vertical profiles of atmospheric temperature, pressure, the aerosol backscatter ratio, and the aerosol extinction coefficient simultaneously. We describe a system with these characteristics. The transmitter is a narrow-band (FWHM of the order of 74 MHz), injection-seeded, pulsed, double YAG laser at 532 nm. Iodine-vapor filters in the detection system spectrally separate the molecular and aerosol scattering and greatly reduce the latter (−41 dB). Operating at a selected frequency to take advantage of two neighboring lines in vapor filters, one can obtain a sensitivity of the measured signal-to-air temperature ratio equal to 0.42%/K. Using a relatively modest size transmitter and receiver system (laser power times telescope aperture equals 0.19 Wm2), our measured temperature profiles (0.5–15 km) over 11 nights are in agreement with balloon soundings to within 2.0 K over an altitude range of 2–5 km. There is good agreement in the lapse rates, tropopause altitudes, and inversions. In principle, to invert the signal requires a known density at one altitude, but in practice it is convenient to also use a known temperature at that altitude. This is a scalable system for high spatial resolution of vertical temperature profiles in the troposphere and lower stratosphere, even in the presence of aerosols.
© 2001 Optical Society of America
[Optical Society of America ]
(010.1280) Atmospheric and oceanic optics : Atmospheric composition
(010.3640) Atmospheric and oceanic optics : Lidar
(280.1100) Remote sensing and sensors : Aerosol detection
(280.3640) Remote sensing and sensors : Lidar
John W. Hair, Loren M. Caldwell, David A. Krueger, and Chiao-Yao She, "High-Spectral-Resolution Lidar with Iodine-Vapor Filters: Measurement of Atmospheric-State and Aerosol Profiles," Appl. Opt. 40, 5280-5294 (2001)