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Performance Improvements to the Lidar Atmospheric Sensing Experiment (LASE)Lidar Atmospheric Sensing Experiment (LASE) is the first fully-engineered, modular, tunable, autonomous Differential Absorption Lidar (DIAL) system for the remote measurement of water vapor, aerosols and clouds across the troposphere. It was designed, built and environmentally tested at LARC. LASE was designed to fly aboard a NASA/Ames ER-2 aircraft (NASA's high altitude aircraft) and operate at altitudes from 58,000 to 70,000 feet. Since its first flight on May 11, 1994, it has flown 28 total missions on board the ER-2. LASE has been validated with results showing an accuracy better than the initial requirement for vertical profiles of water vapor in the troposphere. LASE can also deploy on several other aircraft including the NASA P-3 and will fly aboard the NASA DC-8 during the Convection And Moisture EXperiment (CAMEX) in July-September 1998. The tunable laser system of LASE was designed to operate in a double-pulse mode at 5Hz, with energy outputs of up to 15OmJ per pulse in the 813 to 819nm wavelength region and with 99% of the output energy within a spectral interval of 1.06 pm. Sixteen wavelengths were selected to cover the various water vapor absorption cross sections needed for the DIAL measurement. The Ti:Sapphire laser was constructed using a frequency-doubled Nd:YAG laser as the pump source and a single mode diode laser as a injection seeder for the Ti:Al2O3 laser. We have improved the LASE instrument in several important ways. Improvements to the seed source have demonstrated that DFB laser diodes can be used as reliable seed sources on airborne DIAL instruments. The DFB diode has enabled LASE to gather more data and significantly reduced the maintenance required to insure that the system performance requirements are met. The multiwavelength sequential seeding technique is the current method of data collection for LASE. It has the advantages of providing an entire atmospheric coverage of H2O(v) from the ground to the aircraft altitude along a single ground track. The development of a flight deployable system to measure spectral purity will insure that the LASE instrument or any future flight based DIAL system can meet the performance specifications to insure data accuracy.
Document ID
Acquisition Source
Langley Research Center
Document Type
Conference Paper
Edwards, W. C.
(NASA Langley Research Center Hampton, VA United States)
Petway, L. P.
(Science Applications International Corp. Hampton, VA United States)
Antill, C. W., Jr.
(NASA Langley Research Center Hampton, VA United States)
Date Acquired
August 18, 2013
Publication Date
July 1, 1998
Publication Information
Publication: Nineteenth International Laser Radar Conference
Issue: Part 2
Subject Category
Instrumentation And Photography
Distribution Limits
Work of the US Gov. Public Use Permitted.
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