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 clouds.

Instrument


CEILOMETER (CHM 15k) at Forschungszentrum Jülich on the roof of the IEK-8 (Institut für Energie- und Klimaforschung: Troposphäre).

Data

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
03/2013 - today Research Center Jülich, Germany TR32

Specifications

See manual section 3, 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±1001)
Beam diameter expanded to: 90 mm
Laser divergence < 0.3 mrad
FOV Receiver 0.45 mrad
range gate length 15m
Voltage 230VAC, +/- 10 % / 50 Hz
Max. power consumption 0,8 kW (all heater are running)
Manufacturer Jenoptik
1) varies in time
instruments/ceilo/ceilometer_jen.txt · Last modified: 2016/09/05 17:40 by jan
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