Four example nights that show the effect of the LIDAR corrections. Left column: LIDAR profiles in the form of range-corrected photo-electron counts for four example nights. The consecutive profiles are marked by different color shadings and provide a sample every 4 min. Center column: Resulting integral aerosol transmission curves, T_aer(h). Right column: SEDs of concurrent observations of the Crab Nebula shown without (red) and with (blue) LIDAR correction. For comparison, the reference spectrum of the corresponding period is shown as a dashed green line.