A survey of laser and selected optical systems for remote measurement of pollutant gas concentrations

Abstract

A survey is presented of remote sensing of pollutant gases based on the Differential Absorption Lidar (laser radar) or DIAL technique, in which the differential absorption of two laser beams reflected back to a receiver from some target is used to determine the concentration of the gas being studied. Systems which have undergone extensive laboratory development and field demonstration are emphasized. The laser systems discussed include: dye lasers for SO2, O3, and NO2; carbon dioxide lasers for O3 and C2H4; helium neon lasers for CH4; and tunable diode lasers for a number of gases. A brief discussion of passive optical remote sensors such as Fourier-transform infrared spectrometers, correlation spectrometers (COSPEC and GASPEC), and grating spectrometers is included for comparison. © 1983 Air & Waste Management Association.