Application of inverse filtering on lidar signals

Lidar is a well established remote sensing method. One gets range resolved information from remote location. Ranging, cloud ceiling, aerosol layer identification are a few examples. Using a lidar from satellites gives topographic maps of the Earth's surface (Degnan 1997). For environmental purposes the aerosol smoke stack emission canbe monitored (Measures 1983, Klein und Werner 1993). The measuring principle is based onthe time measurementof a laser pulse reflected froma target. Targets canbe hard targets like the Earth's surface or diffuse targets like clouds. The backscattered signal contains the information on the density characteristics of diffuse targets or the reflection characteristics of the hard target. The range resolution depends onthe pulse characteristics transmitted. In the lidar application the range resolution Lx is proportional to the laser pulse length zt: 2 Therefore, for satellite laser ranging short pulses are used to get resolution in the order of centimeters (for example t =200 ps gives 3 cm resolution for a single event). Can one get the same resolution with a longer pulse? -is one of the questions this paper focusses on. The second question is the identification of aerosol concentrations with high range resolution.