Abstract

A lidar instrument based on pulsed carbon dioxide (CO₂) lasers has been applied to the measurement of atmospheric CO₂ concentration in the earth’s boundary layer. Two lines of the usual 9 μm P branch CO₂ laser are translated to two wavelengths near 4.88 μm by a frequency doubling crystal for this measurement. One frequency-doubled line is strongly absorbed by atmospheric CO₂ and the other acts as a reference in a conventional differential absorption lidar (DIAL) technique. Measurement of transmitter and receiver pulse energy on these two lines provide data necessary for computation of the differential absorption of a horizontal column of the earth’s atmosphere. Inversion of this data using CO₂ spectroscopy results in a measure of CO₂ concentration. Both laboratory data and demonstration field measurements have recently been made and results to date are presented and discussed.

© 1983 Optical Society of America