Accession Number : ADA180622

Title :   Measuring Atmospheric Extinction and Backscatter with a High Spectral Resolution Lidar.

Descriptive Note : Final rept. 1 May 84-30 Nov 86,

Corporate Author : WISCONSIN UNIV-MADISON DEPT OF METEOROLOGY

Personal Author(s) : Eloranta,Edwin W. ; Grund,Christian J.

Report Date : 25 APR 1987

Pagination or Media Count : 103

Abstract : The University of Wisconsin High Spectral Resolution Lindar (HSRL) is designed to make unambiguous, remote measurements of extinction cross sections and backscatter phase functions. This investigation was planned to observe the dependence of aerosol scattering properties on relative humidity. A series of observations were performed. These data showed the expected increase of scattering cross section with increases in relative humidity. In addition the measurements showed that the backscatter phase function appeared to be constant while the total scattering cross section varied. This was a puzzling result. Mean particle size in an aerosol haze should increase with relative humidity; Mie scattering calculations predict that the backscatter phase function is a function of the mean size. A careful analysis of the measurement confidence limits indicated that we could not eliminate calibration uncertainties were unacceptable. At this point we changed the focus of our effort from measurements to instrument improvements.

Descriptors :   *AEROSOLS, *OPTICAL RADAR, *SCATTERING CROSS SECTIONS, BACKSCATTERING, CROSS SECTIONS, EXTINCTION, HIGH RESOLUTION, SPECTRA, MEAN, SIZES(DIMENSIONS), COMPUTATIONS, MIE SCATTERING, SCATTERING, CALIBRATION, PARTICLE SIZE, CONFIDENCE LIMITS, HUMIDITY, MEASUREMENT, REMOTE SYSTEMS, OBSERVATION

Subject Categories : Active & Passive Radar Detection & Equipment
      Atmospheric Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE