LASE

 

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LASE

Points of Contact:

Edward V. Browell & Syed Ismail

NASA Langley Research Center

M.S. 401A

Hampton, Virginia 23681

Office Telephone(s): (757) 864-1273, (757) 864-2719

FAX: (757) 864 7790

E-mail: e.v.browell@larc.nasa.gov, syed.ismail@larc.nasa.gov

 

LASE Homepage: https://web.archive.org/web/20131020222803/http://asd-www.larc.nasa.gov/lase/ASDlase.html

Brief Instrument Description of the
Lidar Atmospheric Sensing Experiment (LASE)

The Lidar Atmospheric Sensing Experiment (LASE) uses the Differential Absorption Lidar (DIAL) technique for simultaneous water vapor and aerosol profile measurements over the entire troposphere. LASE is an autonomous DIAL system that flies on the NASA ER-2 aircraft. The LASE system operates in the 815-nm wavelength region and uses a double pulsed Ti:sapphire laser that is locked onto a water vapor line. The LASE signal processor uses a multi-detector/digitizer system to preserve signal precision, cover a large signal dynamic range, and to minimize signal overload recovery effects. The LASE system has undergone five flight series including an extensive LASE Validation Field Experiment at NASA Wallops Flight Facility (WFF) during September 1995 and a LASE flight series in conjunction with the Tropospheric Aerosol Radiative Observational Experiment (TARFOX) at WFF during July 1996. LASE system has proven to be capable of measuring water vapor profiles over the entire troposphere with high accuracy during both day and night background conditions. The LASE system is also a very sensitive profiler of atmospheric aerosol backscatter over the 0-18 km altitude region. Current plans are to reconfigure LASE for operation from NASA DC-8 and P-3 aircraft besides retaining capability to fly on the ER-2. The capabilities of LASE are listed in Table 1.

References:

        Browell, E.V., et al., 1996: LASE Validation Experiment and Atmospheric Case Studies 18^th Int. Laser Radar Conf., Abstracts, P-31, July 22-26.
        Browell E.V., et al., 1994: Differential Absorption Lidar Measurements of Water Vapor, IGARSS'94, California Inst. Tech., Pasadena, CA, Aug. 8-12.
        Ismail, S., Browell, E. V., 1993: Recent Developments Towards the Deployment of NASA LASE Water Vapor System, Conf. Proceeds., CO-MEAS, pp 142-145, March 22-25.

Table 1: LASE WATER VAPOR AND AEROSOL PROFILING CAPABILITY

(CAMEX MISSIONS ON DC-8 OR ER-2)

Water Vapor:   Altitude Coverage* Measurement Capability Measurement Range Accuracy (Mixing Ratio) Resolution	Ground to tropopause Day and night 0.01 G/KG to 20 G/KG Better than 10% (or 0.01 G/KG) 10 KM (Horizontal) and 0.3 KM (Vertical)
Aerosol Backscatter (815 -NM):   Altitude Coverage* Measurement Capability Measurement Range Precision Resolution	Ground to lower stratosphere Day and night 0.2 to >100 (Aerosol scattering ratios (S/R)) Better than 3% (or 0.2 S/R) 0.2 KM (Horizontal) and 0.3 KM (Vertical)

*Water vapor and aerosol measurements with the exception of a region within +/- 1 KM aircraft altitude due to near field signal overlap/saturation considerations.