Accession Number : AD0675153

Title :   MONTE CARLO ANALYSIS OF SEARCHLIGHT SCATTERING MEASUREMENTS,

Corporate Author : RADIATION RESEARCH ASSOCIATES INC FORT WORTH TEX

Personal Author(s) : Wells,Michael B.

Report Date : 31 MAY 1968

Pagination or Media Count : 23

Abstract : A Monte Carlo analysis was made of measurements of the scattered light from a searchlight beam. These measurements, reported by Elterman (AFCRL-66-828), were performed to determine the aerosol properties of the atmosphere for altitudes below 35 km. Elterman derived altitude profiles of the aerosol attenuation coefficient from the measured response data by use of single scattering theory for Rayleigh and aerosol particle scattering. A study was made using the LITE-I Monte Carlo code to investigate the effects of multiple scattering and ozone absorption on the measured response data for 0.55 micrometer wavelength light. Also studied was the effect on the calculated receiver response that results from the use of different aerosol phase functions in the Monte Carlo calculations. The Monte Carlo calculations showed that the effects of multiple scattering and ozone absorption were approximately equal in magnitude, but opposite in effect, thus one can conclude that the neglect of ozone absorption and multiple scattering did not introduce any significant error in Elterman's calculations of the aerosol attenuation coefficient profiles. The major source of error in determining the aerosol attenuation coefficient profile from single scattering theory was found to be in the use of an aerosol phase function that was measured at a different time and geographical location than that used for the searchlight experiment. (Author)

Descriptors :   (*LIGHT TRANSMISSION, SCATTERING), (*ATMOSPHERES, AEROSOLS), SEARCHLIGHTS, MONTE CARLO METHOD, ATMOSPHERE MODELS, ABSORPTION, ATTENUATION, OZONE, ERRORS

Subject Categories : Atmospheric Physics
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE