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Status of Observations at Chilbolton (CFARR) October 2004. Millimetre cloud radars at CFARR. 94 GHz radar in cradle and 35 GHz radar on mount. Status of millimetre wave cloud radars: 94 GHz Galileo radar has been experiencing loss of transmitter power and
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Status of Observations at Chilbolton (CFARR) October 2004
Millimetre cloud radars at CFARR 94 GHz radar in cradle and 35 GHz radar on mount
Status of millimetre wave cloud radars: • 94 GHz Galileo radar has been experiencing loss of transmitter power and • apart from a few days of operation it has been switched-off since 9th April 2004. • Recent malfunction of the receiver is currently under investigation. • 35 GHz Copernicus radar has been operating since early May 2004. The • radar has two modes of operation: transmitting (1) coded and (2) uncoded pulses. By adopting the pulse compression mode it is possible to improve sensitivity by ~10dB. The radar measures: Full Doppler spectrum, the spectral moments and the polarimetric parameters
Specification of 35 GHz Copernicus radar: • Transmitter is based on a programmable waveform generator driving a • high-power pulsed amplifier tube (EIKA). • The receiver is a dual channel, double-conversion superheterodyne with • separate IF chains for simultaneous co-polar and cross-polar measurements. • Dual-polarisation antenna (2.4 m) includes a fast transmit polarisation switch. • Tx power 1.5 kW peak pulse • Range resolution 75 metres • Beamwidth 0.23 degrees • PRF 5000 Hz • Unambiguous velocity ~5.3 m/s • Minimum range in pulse compression mode ~500 metres
35 GHz Copernicus radar data Uncoded pulse Coded pulse [Pulse Compression Gain ~10dB] velocity away from radar radar reflectivity
35 GHz Copernicus radar data Uncoded pulse Coded pulse [Pulse Compression Gain ~10dB] velocity away from radar radar reflectivity
UV Raman Lidar IR Lidar CT75K Ceilometer collects backscatter Lidars Radiosonde comparisons with integrated water vapour profile performed during July 2004
Pyrgeometer & Pyranometer Broadband Radiometers Radiometers Microwave radiometers Retrieving LWP and IWV From 22.2 and 28.8 GHz [37.5 GHz under investigation for instability]
FMCW - low power radar Additional measurements: One month of data. Comparison of performance between pulsed radar and low power FMCW unit (100mw Tx power) Two examples: