Measurements of source emissions and ambient air quality using pulsed nitrogen and dye lasers

A lidar system for the study of atmospheric pollutants has been constructed and tested. A dye laser pumped by a nitrogen laser and a flashlamp-pumped dye laser are incorporated in the system. A 25-cm-diameter telescope is used as a receiver. The telescope, which has its axis parallel to the laser output beam, may be directed via a computer, which also sets the laser wavelength. Measurements are made in a signal-averaging process, and calculations are made in real time by the computer. The methods used for measurements of molecular constituents are based on the DIAL technique, whereas other studies are made using mainly elastic but also Raman scattering. Studies of smokestack emissions have been made for particles and the gases NO2 and SO2 at different industrial plants. Plume-spreading studies of very faint plumes have been performed. NO2 and SO2 have further been studied in an urban atmosphere.