Accession Number : AD0693493

Title :   REPORT OF THE MOUNT HALEAKALA OBSERVATORY: FLUORESCENCE AS A SOURCE OF NOISE IN Q-SWITCHED RUBY LASER ATMOSPHERIC BACKSCATTERING EXPERIMENTS,

Corporate Author : MICHIGAN UNIV ANN ARBOR INST OF SCIENCE AND TECHNOLOGY

Personal Author(s) : McCormick,P.

Report Date : SEP 1969

Pagination or Media Count : 22

Abstract : Interpretation of the results of atmospheric backscattering experiments, when using a Q-switched ruby laser as the source of photons, requires consideration of several sources of noise in the statistical analysis. This report discusses the effects of directly backscattered ruby fluorescence in detail. It is found that, for an unshuttered system, fluorescence noise will be equal to the signal expected from altitudes above about 50-60 km (assuming only a molecular atmosphere). The 'crossover' altitude is lowered if aerosols are present. When a shutter is used as a fluorescence block, it is found that a spurious 'layer' structure may be produced--but only for shutter cutoff times of greater than about 375 microseconds. It is concluded that, for a properly designed optical radar system, ruby fluorescence will not be a significant source of spurious returns. In particular, it is concluded that this source will not explain the enhanced returns from altitudes of about 80 km observed by McCormick. (Author)

Descriptors :   (*OPTICAL RADAR, LASERS), (*ATMOSPHERIC SOUNDING, *LASERS), RUBY, FLUORESCENCE, BACKSCATTERING, NOISE(RADIO), SHUTTERS(OPTICS)

Subject Categories : Atmospheric Physics
      Lasers and Masers
      Optical Detection and Detectors

Distribution Statement : APPROVED FOR PUBLIC RELEASE