Backscatter and Transmission of Aerosol at UV through Middle IR wavelengths

Abstract

Simultaneous measurements of backscatter and transmission coefficients, sigma b and sigma e for obscuring and biological aerosols using a Nd:Yag pulsed laser system at 1064, 532, and 266 nm wavelengths are being investigated in the laboratory. Forward scattering measurements are obtained at wavelengths 1064 and 532 nm for water droplet polydispersions and compares favourably with theoretical values for relatively narrow size distributions. However, for broader size distribution, the contribution by forward scattered radiation to the estimation signal is significant and needs to be accounted for in extinction and backscatter measurements. The aerosol chamber for obscuring (carbon powder) aerosol is described. Measurements of pollen and spore biological aerosol using an array of passive Tauber traps are presented. Percentage counts as well as species concentration values are given for seven sites in the west of Ireland covering the period from November 1992 through May 1993. Backscatter, Transmission, Biological aerosol, Spore, Pollen.

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Document Details

Document Type
Technical Report
Publication Date
Dec 21, 1993
Accession Number
ADA277179

Entities

People

  • S. G. Jennings

Organizations

  • University of Galway

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Aerosols
  • Anhydrides
  • Backscattering
  • Biological Aerosols
  • Chambers
  • Coefficients
  • Detectors
  • Extinction
  • Forward Scattering
  • Fungi
  • Laser Beams
  • Lasers
  • Measurement
  • National Parks
  • Particle Size
  • Pulsed Lasers
  • Scattering

Fields of Study

  • Physics

Readers

  • Aerosol Science/Aerosol Physics
  • Spectroscopy.

Technology Areas

  • Directed Energy
  • Directed Energy - Lasers