Analysis of the receiver response in lidar measurements

We report on the calculation of the effective telescope area in lidar applications by a ray-tracing approach. This method allows one to consider the true experimental working conditions and hence to obtain accurate values of the effective telescope area as a function of the height. This in turn allows the retrieval of the signal from the ranges where the overlap function is not constant (e.g., lower ranges), thus increasing the useful range interval. Moreover, we show that the spherical mirrors are more appropriate than the parabolic ones for most of the lidar measurements, although a particular alignment procedure, such as the one we describe, must be used.