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instruments:ceilo:ceilometer

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instruments:ceilo:ceilometer [2020/02/06 09:02]
jan
instruments:ceilo:ceilometer [2020/02/06 09:09] (current)
jan [Principle]
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 ===== Principle ===== ===== 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.+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 from the backscatter coefficient ​and identifying the height from which on you cant see the ground any more. If the lower clouds are transparent it can detect up to three distinct cloud layers. ​In clud free cases we can use the backscatter profile for an estimate of boundary layer height.
  
 ===== Instrument ===== ===== Instrument =====
instruments/ceilo/ceilometer.1580976146.txt.gz ยท Last modified: 2020/02/06 09:02 by jan