DIFFERENTIAL ABSORPTION LIDAR MEASUREMENT OF VERTICAL OZONE PROFILES IN THE TROPOSPHERE THAT CONTAINS AEROSOL LAYERS WITH STRONG BACKSCATTERING GRADIENTS - A SIMPLIFIED VERSION

A technique for determining approximate ozone-concentration profiles from differential absorption lidar (DIAL) data obtained in the troposphere with large gradients of aerosol backscattering is presented. The atmospheric interferences are defined as errors of the off-on DIAL signal ratio; the interferences are separated and removed before the ratio is differentiated. To facilitate the separation of the regular (subjected to differentiation) component of the signal ratio from random noise, the ratio is transformed into an intermediate function, and the measurement error is minimized by fitting of an analytical function to the transformed function. Simple criteria are used to demarcate atmospheric layering, for which a strong aerosol-backscattering gradient can result in an unacceptably large error in the measured ozone concentration.