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Differential Absorption Measurements of Atmospheric Water Vapor with a Coherent Lidar at 2050.532 nmWind and water vapor are two major factors driving the Earth's atmospheric circulation, and direct measurement of these factors is needed for better understanding of basic atmospheric science, weather forecasting, and climate studies. Coherent lidar has proved to be a valuable tool for Doppler profiling of wind fields, and differential absorption lidar (DIAL) has shown its effectiveness in profiling water vapor. These two lidar techniques are generally considered distinctly different, but this paper explores an experimental combination of the Doppler and DIAL techniques for measuring both wind and water vapor with an eye-safe wavelength based on a solid-state laser material. Researchers have analyzed and demonstrated coherent DIAL water vapor measurements at 10 micrometers wavelength based on CO2 lasers. The hope of the research presented here is that the 2 gm wavelength in a holmium or thulium-based laser may offer smaller packaging and more rugged operation that the CO2-based approach. Researchers have extensively modeled 2 um coherent lasers for water vapor profiling, but no published demonstration is known. Studies have also been made, and results published on the Doppler portion, of a Nd:YAG-based coherent DIAL operating at 1.12 micrometers. Eye-safety of the 1.12 micrometer wavelength may be a concern, whereas the longer 2 micrometer and 10 micrometer systems allow a high level of eyesafety.
Document ID
20000012964
Document Type
Conference Paper
Authors
Koch, Grady J. (NASA Langley Research Center Hampton, VA United States)
Dharamsi, Amin (Old Dominion Univ. Norfolk, VA United States)
Davis, Richard E. (NASA Langley Research Center Hampton, VA United States)
Petros, Mulugeta (Science and Technology Corp. Hampton, VA United States)
McCarthy, John C. (Sanders Associates, Inc. Nashua, NH United States)
Date Acquired
August 19, 2013
Publication Date
November 1, 1999
Publication Information
Publication: Tenth Biennial Coherent Laser Radar Technology and Applications Conference
Subject Category
Meteorology and Climatology
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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