THEORETICAL STUDY OF A TWO-WAVELENGTH LIDAR TECHNIQUE FOR THE MEASUREMENT OF ATMOSPHERIC TEMPERATURE PROFILES.

Abstract

THE THEORY OF DIFFERENTIAL ABSORPTION LIDAR MEASUREMENTS FOR LINES WITH A VOIGT PROFILE IS GIVEN AND APPLIED TO A TWO-WAVELENGTH TECHNIQUE FOR MEASURING THE ATMOSPHERIC TEMPERATURE PROFILE USING A HIGH J LINE IN THE OXYGEN A BAND. EXPLICITEXPRESSIONS FOR THE TEMPERATURE AND PRESSURE DEPENDENCE OF THE ABSORPTION COEFFICIENT ARE DEVELOPED FOR LINES WITH A VOIGT PROFILE. AN ITERATION PROCEDURE FOR CALCULATING THE TEMPERATURE FOR NARROW LASER BANDWIDTH IS DESCRIBED WHICH HAS ANACCURACY BETTER THAN 0. 2 K FOR BANDWIDTHS < 0. 01 CM** - **1. TO REDUCE THE ERRORS IN LIDAR MEASUREMENTS DUE TO UNCERTAINTIES IN PRESSURE, A METHOD IS DESCRIBED FOR ESTIMATING THE PRESSURE FROM THE TEMPERATURE PROFILE. ALSO DESCRIBED IS APROCEDURE FOR EXTENDING THE DIFFERENTIAL ABSORPTION TECHNIQUE TO THE CASE OF FINITE LASER BANDWIDTH WITH GOOD ACCURACY.