UV Raman lidar Chilbolton Observatory Review April 2003-2004

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UV Raman lidarChilbolton ObservatoryReview
April 2003-2004
Judith Agnew CCLRC Rutherford Appleton
Laboratory Radio Communications Research Unit
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Summary of events

• CWAVE campaign June-July 2003 comparison of UV
  Raman lidar data with Met Office Radiometrics
  radiometer and co-located Aberystwyth
  polarimetric lidar.
• Examples of high cirrus cloud.
• Laser repair.
• Implementation of new data acquisition system.

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Lidar, radiometer, radiosonde humidity mixing
ratio
Average signal in each radiometer range bin
during lidar measurement period
Lidar
Radiometer
Radiosonde
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Water vapour measurements
13/06/03
Raman lidar
Radiometer
Difference
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Water vapour measurements
25/06/03
Raman lidar
Radiometer
Difference
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High cirrus clouds
07/05/03
09/06/03
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Lidar upgrades

• New data acquisition system about to be
  delivered. Installation work to begin
  immediately, while keeping existing system
  operational.
• Will upgrade the capabilities from 8 bit analog
  to 12 bit analog and photon counting
• Photon counting will improve the measurement of
  small signals, especially by night.
• Higher resolution analog measurements beneficial
  when photon counting is not suitable, for example
  by day in the Raman scattering channels.
• Laser underwent extensive maintenance and now has
  much improved beam power.