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--- instruments:ceilo:ceilometer_jen [2013/03/07 14:24] – rainer
+++ instruments:ceilo:ceilometer_jen [2021/01/22 22:17] (current) – external edit 127.0.0.1
@@ Line 1: / Line 1: @@
 ====== Ceilometer Jenoptik CHM15k Nimbus ======
-//Mentor: NN//
+//Mentor: [[http://www.geomet.uni-koeln.de/das-institut/mitarbeiter/schween/|J.H. Schween]]//
 ===== Principle =====
-A ceilometer measures the cloud base height, i.e. the //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 the strong increase of the backscatter coefficient. If the lower clouds are transparent it can detect up to three distinct cloud layers. We use the backscatter profile for an estimate of boundary layer height.
+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 clouds.
 ===== Instrument =====
 {{:instruments:ceilo:chm15k.jpg?200|}}\\
-Current setup at [[http://www.fz-juelich.de/|Research Center Jülich]] on the roof of IEK-8:  [[http://www.jenoptik.com/en_40156_chm_15k_family|Jenoptik]] CHM15k ceilometer.
+CEILOMETER (CHM 15k) at [[http://www.fz-juelich.de/|Forschungszentrum Jülich]] on the roof of the IEK-8 ([[http://www2.fz-juelich.de/icg/icg-2/|Institut für Energie- und Klimaforschung: Troposphäre]]).
 ===== Data =====
+  * If you are interested in receiving data please contact: [[http://www.geomet.uni-koeln.de/allgemein/das-institut/mitarbeiter/detailansicht/f93e43fbbe15a16f8a85792ec07ed119/?tx_wtdirectory_pi1[show]=42&tx_rggooglemap_pi1[poi]=42|U. Löhnert]]
+  * [[http://atmos.meteo.uni-koeln.de/~hatpro/dataBrowser/dataBrowser2.html?site=JOYCE&date=-1&UpperLeft=Ceilo_chm15k_raw&UpperRight=Ceilo_chm15k_uncalibrated&LowerRight=default&LowerLeft=default|quicklook archive]]
+  * Current observations:
+<html>
+<center>
+<a href="http://atmos.meteo.uni-koeln.de/~hatpro/jue/ceilo/jenopt/" target="_blank">
+<img src="http://atmos.meteo.uni-koeln.de/~hatpro/jue/ceilo/jenopt/ceilo_jenoptik.png" width=420>
+</a>
+</center>
+</html>
+The figure shows raw backscatter signal as functions of time and height. Red curves indicate cloud base heights and blue curves indicate aerosol layer heights as derived by the measurement software.
 ===== History ====
 ^  Period  ^  Place  ^  Project  ^
@@ Line 17: / Line 29: @@
 ===== Specifications =====
+See manual section 3, {{:internal:instruments:ceilometer:manual_chm15k.pdf#11| page 11 }}.
 ^  Parameter  ^  Specification  ^
 | Wavelength | 1064 nm |
 | Bandwidth | 0.1 nm |
+| Energy per pulse | 8µJ |
+| Long-time stability over 12 month (prr) | < 10 % |
+| Pulse to pulse variance of laser energy| < 3 % |
 | Pulse duration | 1 ... 5 ns |
 | Pulse repetition rate (prr) | 5 - 7 kHz |
+| Number of pulses per profile | 105650±100((varies in time)) |
 | Beam diameter | expanded to: 90 mm |
 | Laser divergence | < 0.3 mrad |
-| Energy per pulse | 8µJ |
-| Long-time stability over 12 month (prr) | < 10 % |
-| Pulse to pulse variance of laser energy| < 3 % |
 | FOV Receiver | 0.45 mrad |
+| range gate length | 15m |
+| temporal resolution | 15sec |
 | Voltage | 230VAC, +/- 10 % / 50 Hz |
 | Max. power consumption | 0,8 kW (all heater are running) |
+| Manufacturer | [[http://www.jenoptik.com/en_home|Jenoptik]] |