A C-band mobile polarimetric radar with simultaneous horizontal and vertical transmission was built in the State Key Laboratory of Severe Weather,Chinese Academy of Meteorological Sciences.ft was used in heavy rainfall and typhoon observations in 2008.It is well-known that radar calibration is essential and critical to high quality radar data and products.In this paper,the test and weather signals were used in calibration of reflectivity Z_H,differential reflectivity Z_(DR),and differential phaseΦ_(dp).Noise effects on correlation coefficient phv at low signal-noise-ratio(SNR)were analyzed.The polarimetric radar data for a heavy rain and a snow event were inspected to evaluate the performance of the calibration method and radar data quality,and S-band Doppler radar data were used to validate the reflectivity data quality collected by the polarimetric radar.The results show that the polarimetric and S-band Doppler radars have observed comparable reflectivity values and a similar structure of a heavy rainfall case at middle and low levels.The mismatch of two receivers produce obvious Z_(dr)biases,which were verified by the radar data observed at vertical incidence.The Z_(dr)correction improved the radar data quality.The usage range for phv was defined.Application of the calibration method introduced in this paper can reduce the system biases caused by the difference of horizontal(H)and vertical(V)channels.After the calibration and correction,the polarimetric parameters observed by the polarimetric radar could be used in further relevant researches.
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