https://atmos.meteo.uni-koeln.de/ag_crewell/ 2026-04-12T19:35:12+00:00 https://atmos.meteo.uni-koeln.de/ag_crewell/ https://atmos.meteo.uni-koeln.de/ag_crewell/lib/exe/fetch.php?media=wiki:logo.png text/html 2025-08-26T08:19:22+00:00 Anonymous (anonymous@undisclosed.example.com) https://atmos.meteo.uni-koeln.de/ag_crewell/doku.php?id=instruments:ceilo:ceilometer&rev=1756196362&do=diff Ceilometer CT25K Mentor: J.H. Schween Principle A ceilometer measures the cloud base height, called ceiling in aviation. It is based on the light detecting and ranging (LIDAR) principle, i.e. it sends laser pulses and measures the backscattered light. From travel time the distance of the back scattering object can be determined. From strength and attenuation of the backscattered signal the backscatter coefficient is determined. The instrument identifies cloud bases by caluclating visibility f… text/html 2024-08-02T08:17:54+00:00 Anonymous (anonymous@undisclosed.example.com) https://atmos.meteo.uni-koeln.de/ag_crewell/doku.php?id=instruments:ceilo:ceilometer_jen&rev=1722586674&do=diff Ceilometer Jenoptik CHM15k Nimbus Mentor: J.H. Schween Principle The CHM 15k ceilometer is a robust, autonomous and low power lidar for measuring vertical profiles of backscatter signal from aerosol particles and hydrometeors. From the backscatter profiles cloud base heights and signal penetration depths, aerosol layer heights and vertical visibility are determined. Within its operating range up to 15 kilometers (50,000 feet), the CHM 15k reliably detects multiple cloud layers and cirrus clou… text/html 2021-01-22T21:17:14+00:00 Anonymous (anonymous@undisclosed.example.com) https://atmos.meteo.uni-koeln.de/ag_crewell/doku.php?id=instruments:ceilo:dwd_jenoptik&rev=1611350234&do=diff DWD Jenoptik Ceilometer @ Jülich In 2009 the TR32 could lent a Jenoptik CHM 15K Ceilometer owned by DWD. The instrument was serviced by Martin Lennefer from the Meteorological Institute of the University Bonn. It was installed at the FZ-Jülich at text/html 2021-01-22T21:17:14+00:00 Anonymous (anonymous@undisclosed.example.com) https://atmos.meteo.uni-koeln.de/ag_crewell/doku.php?id=instruments:ceilo:jenoptik_ip&rev=1611350234&do=diff =========================================================================== JuNet-DB-Auszug: IEK8291 (eingetragen: 18-FEB-13) =========================================================================== Host-ID: IEK8291 Seriennummer: - Host-Type: Ceilometer_CHM_15k Host-Class: PC Personenbez. Daten: N Gebaeude / Raum: 05.2 / Dach Administrator: Decker,Michael (IEK-8, FZJ-3867) Email… text/html 2021-01-22T21:17:14+00:00 Anonymous (anonymous@undisclosed.example.com) https://atmos.meteo.uni-koeln.de/ag_crewell/doku.php?id=instruments:ceilo:recent_data&rev=1611350234&do=diff Ceilometer Recent Data Quicklooks Vaisala CT25K in Selhausen: 2007 jan feb mar apr may jun jul aug sep oct nov dec 2008 jan feb mar apr may jun jul aug sep oct nov dec 2009 jan feb mar text/html 2021-01-22T21:17:14+00:00 Anonymous (anonymous@undisclosed.example.com) https://atmos.meteo.uni-koeln.de/ag_crewell/doku.php?id=instruments:ceilo:sel_ceilo_comparison&rev=1611350234&do=diff compare CL31(Sel) and CHM15K(Jue) Between April and September 2009 a Vaisala and a Jenoptic Ceilometer were running in Selhausen and Jülich ~2km apart from each other. The instrument in Selhausen changed two times: * till April 30 7 UTC it was a Vaisala CT25K borrowed from the Met.Inst.of Univ. Bonn.