Performance improvement of long-range scanning Mie lidar for the retrieval of atmospheric extinction

To improve the detection range and signal to noise ratio in the remote sensing of atmospheric processes using long-range scanning Mie lidar, simultaneously obtained analog (A) and photon-counting (P) data traces were merged using a novel gluing method based on the modification of the A trace so that it follows Poisson statistics. In comparison with the traditional method based on the minimization of the distance between A and P, the advantage of this new approach is an improved uniformity of the merged data trace as well as a reduced influence of atmospheric conditions on the obtained transfer coefficients. The atmospheric extinction was subsequently retrieved using the two- and multi-angle method. The offset of the laser beam direction was calibrated against a self-leveling laser, as an offset in elevation angle was found to produce considerable error in the atmospheric extinction profiles obtained under the assumption of horizontal atmospheric homogeneity.

► Characteristics of analog and PC data trace were evaluated by variance calculation. ► PC data trace is Poissonian distributed, while analog data trace is linear shifted. ► Novel gluing method by modifying analog data to follow Poissonian was investigated. ► Lidar elevation angle was horizontally calibrated against a self-leveling laser. ► Small angular offset was found to have a visible impact on atmospheric extinction.