Data from the Met Office's laser cloud base recorders network (LCBRs), or ceilometers, returns a range of products for use in forecasting and hazard detection. These include cloud base height and also backscatter profiles. The backscatter profiles can allow detection of aerosol species such as volcanic ash where suitable instrumentation is deployed. The Met Offices operational LIDARNET network consists of Vaisala CT25k and CL31 ceilometers and the Jenoptik CHM15k Nimbus. In addition, this dataset also contains data from the development ceilometers operated by the Met Office.