COMBINED RAMAN-ELASTIC BACKSCATTER LIDAR METHOD FOR THE MEASUREMENT OF BACKSCATTER RATIOS

A variation of the conventional combined Raman-elastic backscatter lid ar method, the 1-2-3 lidar method, is described and analyzed. This met hod adds a second transmitter wavelength to the conventional combined Raman-elastic backscatter lidar. This transmitter wavelength is identi cal to that of the Raman receiver. One can generate the transmitted be am at this wavelength by Raman shifting the laser radiation in molecul ar nitrogen or oxygen. Measuring a second elastic lidar signal at the Raman-shifted wavelength makes it possible to eliminate differential t ransmission effects that can cause systematic errors in conventional c ombined Raman-elastic backscatter lidar. (C) 1997 Optical Society of A merica.