Lidar system using polarization discrimination techniques for molecular air pollution monitoring

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1984

OSTI ID:5316069

Kokkinos, D S

A differential absorption of scattered energy (DASE) Lidar scheme which uses polarization discrimination to distinguish between simultaneously backscattered Lidar return signals at two close lying wavelengths was conceived, analyzed, designed and built into a complete Lidar system. The system was then successfully used to first test our critical basic design premises related to atmospheric backscatter processes, and then to demonstrate its practical viability in field measurements of atmospheric nitrogen dioxide. Lidar outputs are emitted simultaneously at two close-lying wavelengths, orthogonally polarized. The output wavelengths correspond to a peak and trough in the absorption spectrum of the pollutant being monitored. The concentration of pollutant is determined by using polarization discrimination techniques to separate and measure the relative attenuations of the Lidar backscattered signals at each of the wavelengths as they transverse the sample region. The polarization discrimination system was built producing orthogonally polarized laser outputs at two close-lying wavelengths. A similar arrangement was designed for the Lidar receiver, where the separated signals were detected by separate photomultipliers. Finally field experiments were carried out, to measure, from the laboratory window, concentrations of nitrogen dioxide at kilometer ranges over the upper East Side of Manhattan. The results of these experiments, which measured pollution concentrations of low ppm demonstrated the viability of the polarization discrimination DASE Lidar system.

• Research Organization: City Univ. of New York, NY (USA)
• OSTI ID: 5316069
• Country of Publication: United States
• Language: English

Related Subjects

440300 -- Miscellaneous Instruments-- (-1989)
47 OTHER INSTRUMENTATION
500200* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
ABSORPTION SPECTRA
AIR POLLUTION
AIR POLLUTION MONITORING
AIR POLLUTION MONITORS
BACKSCATTERING
CHALCOGENIDES
DESIGN
ECOLOGICAL CONCENTRATION
FEDERAL REGION II
MEASURING INSTRUMENTS
MONITORING
MONITORS
NEW YORK
NEW YORK CITY
NITROGEN COMPOUNDS
NITROGEN DIOXIDE
NITROGEN OXIDES
NORTH AMERICA
OXIDES
OXYGEN COMPOUNDS
POLARIZATION
POLLUTION
SCATTERING
SPECTRA
USA