Exploring the Capabilities of the CHM 15k Ceilometer to Detect Icing Conditions within Clouds

Aircraft icing is a known hazard in the aviation field that results from supercooled liquid water (SLW) in clouds impacting aircraft surfaces. Detecting icing conditions is an important step in keeping aircraft out of harm's way. However, detecting icing conditions aloft can be difficult. In this study, data from a Lufft CHM 15K ceilometer were analyzed to determine if the sensor could detect icing conditions aloft. A CNR1 solar radiation sensor was used to determine cloudy days and a GEONOR 600mm precipitation gauge was used to identify precipitation events on the cloudy days. Each case identified from these sensors was categorized into the days considered for the precipitating and non-precipitating events for this study. PIREPs (pilot reports) are used to provide Air Traffic Control (ATC) and other pilots with a variety of information including encountered weather type, icing severity, altitude, and date/time of occurrence. Icing information from PIREPs was compared against the ceilometer data to investigate whether the ceilometer shows any abilities in detecting icing conditions aloft. The ceilometer data were plotted as a function of time and the raw signal return data were analyzed against the PIREPs to determine if there was any information in the signal that might indicate icing conditions in the atmosphere. Results of this study will be shown and several case studies will be highlighted to show the ceilometers performance during known icing conditions.