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Record Details

Record 48 of 3352
Advanced Raman water vapor lidar
Author and Affiliation:
Whiteman, David N.(NASA Goddard Space Flight Center, Greenbelt, MD, United States)
Melfi, S. Harvey(NASA Goddard Space Flight Center, Greenbelt, MD, United States)
Ferrare, Richard A.(Universities Space Research Association, Columbia, MD., United States)
Evans, Keith A.(Hughes STX, Inc., Lanham, MD., United States)
Ramos-Izquierdo, Luis(NASA Goddard Space Flight Center, Greenbelt, MD, United States)
Staley, O. Glenn(NASA Goddard Space Flight Center, Greenbelt, MD, United States)
Disilvestre, Raymond W.(NASA Goddard Space Flight Center, Greenbelt, MD, United States)
Gorin, Inna(NASA Goddard Space Flight Center, Greenbelt, MD, United States)
Kirks, Kenneth R.(Science Systems and Applications, Inc., Greenbelt, MD., United States)
Mamakos, William A.(Science Systems and Applications, Inc., Greenbelt, MD., United States) Show more authors
Abstract: Water vapor and aerosols are important atmospheric constituents. Knowledge of the structure of water vapor is important in understanding convective development, atmospheric stability, the interaction of the atmosphere with the surface, and energy feedback mechanisms and how they relate to global warming calculations. The Raman Lidar group at the NASA Goddard Space Flight Center (GSFC) developed an advanced Raman Lidar for use in measuring water vapor and aerosols in the earth's atmosphere. Drawing on the experience gained through the development and use of our previous Nd:YAG based system, we have developed a completely new lidar system which uses a XeF excimer laser and a large scanning mirror. The additional power of the excimer and the considerably improved optical throughput of the system have resulted in approximately a factor of 25 improvement in system performance for nighttime measurements. Every component of the current system has new design concepts incorporated. The lidar system consists of two mobile trailers; the first (13m x 2.4m) houses the lidar instrument, the other (9.75m x 2.4m) is for system control, realtime data display, and analysis. The laser transmitter is a Lambda Physik LPX 240 iCC operating at 400 Hz with a XeF gas mixture (351 nm). The telescope is a .75m horizontally mounted Dall-Kirkham system which is bore sited with a .8m x 1.1m elliptical flat which has a full 180 degree scan capability - horizon to horizon within a plane perpendicular to the long axis of the trailer. The telescope and scan mirror assembly are mounted on a 3.65m x .9m optical table which deploys out the rear of the trailer through the use of a motor driven slide rail system. The Raman returns from water vapor (403 nm), nitrogen (383 nm) and oxygen (372 nm) are measured in addition to the direct Rayleigh/Mie backscatter (351). The signal from each of these is split at about a 5/95 ratio between two photomultiplier detectors. The 5 percent detector is used for measurements below about 4.0 km, while the 95 percent detector provides the information above this level.
Publication Date: Jul 01, 1992
Document ID:
19920021796
(Acquired Nov 07, 1995)
Accession Number: 92N31040
Subject Category: INSTRUMENTATION AND PHOTOGRAPHY
Document Type: Conference Paper
Publication Information: NASA. Langley Research Center, 16th International Laser Radar Conference, Part 2; p 483-484
Publisher Information: United States
Financial Sponsor: NASA; United States
Organization Source: NASA Goddard Space Flight Center; Greenbelt, MD, United States
Ressler Associates, Inc.; Laurel, MD, United States
University Research Foundation; Greenbelt, MD, United States
NYMA, Inc.; Greenbelt, MD, United States
Description: 2p; In English
Distribution Limits: Unclassified; Publicly available; Unlimited
Rights: No Copyright
NASA Terms: AEROSOLS; ATMOSPHERIC COMPOSITION; EARTH ATMOSPHERE; EXCIMER LASERS; METEOROLOGICAL PARAMETERS; OPTICAL RADAR; RAMAN SPECTRA; WATER VAPOR; XENON FLUORIDE LASERS; CONVECTION; DATA ACQUISITION; DIGITAL COMPUTERS; GAS MIXTURES; GLOBAL WARMING; LASER APPLICATIONS; MIRRORS; SCANNERS; SCANNING; SURFACE ENERGY; TELESCOPES; TRANSMITTERS
Imprint And Other Notes: In NASA. Langley Research Center, 16th International Laser Radar Conference, Part 2 p 483-484 (SEE N92-31013 21-35)
Miscellaneous Notes: Prepared in cooperation with Ressler Associates, Inc., Laurel, MD; University Research Foundation, Greenbelt, MD; and NYMA, Inc., Greenbelt, MD
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