Accession Number : AD0746280

Title :   A Comparative Study of Laser Methods of Air Pollution Mapping,

Corporate Author : TORONTO UNIV (ONTARIO) INST FOR AEROSPACE STUDIES

Personal Author(s) : Measures,R. M.

Report Date : DEC 1971

Pagination or Media Count : 44

Abstract : A comparative study has been made of three laser methods of remotely mapping gaseous pollutants of the atmosphere. It has been found that, in the case of NO2 and SO2, Differential Absorption and Scattering has superior performance potential with regard to range and sensitivity than either Laser-Induced Fluorescence or Raman Backscattering. However, because of the sophistication of this system and the difficulty of interpretation, it is strongly recommended that from the long term point of view the fluorescence approach be pursued further as it has a range and sensitivity far superior to Raman backscattering for a given laser power. An analysis of the fluorescence return expected from a local source of NO2 indicates that a plume of about 10 ppm could be detected at a range of several kilometers. However, due to absorption effects, care must be used in the interpretation of signals emanating from local concentrations in excess of about 10 ppm. (Author)

Descriptors :   (*AIR POLLUTION, *OPTICAL RADAR), (*GAS DETECTORS, OPTICAL RADAR), (*NITROGEN OXIDES, GAS DETECTORS), GAS LASERS, SCATTERING, FLUORESCENCE, EXCITATION, BACKSCATTERING, RAMAN SPECTROSCOPY, MAPPING, ABSORPTION, MONITORS, RELAXATION TIME, CONCENTRATION(CHEMISTRY), MATHEMATICAL ANALYSIS, CANADA

Subject Categories : Optical Detection and Detectors
      Infrared Detection and Detectors
      Air Pollution and Control

Distribution Statement : APPROVED FOR PUBLIC RELEASE