Ceilometer CHM 15K Nimbus is a LIDAR cloud height sensor based on a single wavelength backscattering technique. It detects various cloud layers (max 9), cloud penetration depths, issues the Sky Condition Index, vertical field of view (VOR), aerosol layer heights, boundary layers and aerosol backscatter profiles with a range of up to 15 km. It is operating at 1min and 15m temporal and spatial resolution and up to 15 kilometers. It reliably detects multiple cloud layers, cirrus clouds, and aerosol layers. Excellent signal performance is achieved by a stable wavelength, narrow line width microship Nd:YAG laser operating at 1064 nm . The data are stored with a temporal resolution of 60 s.