CORRECTION SCHEME FOR EXPERIMENTAL BIASES IN DIFFERENTIAL ABSORPTION LIDAR TROPOSPHERIC OZONE MEASUREMENTS BASED ON THE ANALYSIS OF SHOT PER SHOT DATA SAMPLES

From lidar signals detected with a shot per shot differential absorpti on lidar instrument tuned for tropospheric ozone measurements and reco rding each individual return, we reconstruct histograms of their sampl ed values fbr each channel of our digitizers. The analysis of their sh ape permits the correction of our measurements for experimental biases . In particular, a negative correlation is found between the skew of t he histograms and the intensity of the backscattered light. The skew c omes from a tail at high sampled values, interpreted as due to a raise of the relative contribution to the signal of a signal-induced noise when this intensity diminishes. By fitting a Gaussian function to the histograms without considering their tails, we calculate average signa ls unbiased by the corresponding noise. This approach allows us to inc rease the range of our ozone profiles, up to as much as double it in s ome cases. (C) 1997 Optical Society of America.