Abstract:This paper describes the calibration technology of CINRAD/SA-D dual-polarization Doppler weather radar (dualpolarization radar for short) and statistically analyzes the automatic online calibration data and the maintenance and repair of Jinan dual-polarization radar since its operation. From dozens of performance parameters for radar calibration state, the parameters that have the greatest influence on the quality of radar detection data are selected to analyze and evaluate the quality of automatic online calibration data, including peak power Pt, phase noise σφ, noise figure NF, SYSCAL, differential reflectivity factor ZDR, differential propagation phase shift ΦDP. The results are as follows. 1) When the peak power maintains at 679.68 kW, the peak power of H channel (horizontal) and V channel (vertical) is consistent in long-term operation. 2) The average noise figure of H channel maintains at 1.66 dB and V channel at 1.73 dB, and the overall distribution of dual channel data is stable and has good consistency. The anomaly of the calibration data comes from external interference, accounting for 0.39%. The H channel bears more interference from the external environment than the V channel, which reduces the sensitivity of the receiver by 1.5 dB and makes the radar products abnormal. 3) The minimum value of ΔSYSCAL is -0.46 dB and the maximum is 0.25 dB, which meets the requirements of ±2 dB. 4) The mean value of phase noise calibrated by I/Q phase angle method is 0.051 3°, and the results of the actual object cancellation being 60 dB and the estimated ground clutter suppression ability being 61.36 dB are basically consistent, which proves the radar system has good ability of ground clutter suppression. 5) The CW and TS calibration methods of dual signal sources are used to receive the standard deviations of the amplitude and phase of the two channels, and ZDR-CW, ΦDP-CW, ZDR-TS, and ΦDP-TS are 0.025 dB, 0.735°, 0.044 dB, and 1.116°, respectively, which satisfies the technical indicators of receiving dual channel consistency. However, the calibration results of CW signal are significantly smaller than those of TS signal, which shows the dual channel azimuth rotary joint has an impact on the consistency of the amplitude and phase of the received link signal, resulting in the calibration results of ZDR-TS and ΦDP-TS worse than those of ZDR-CW and ΦDP-CW. Therefore, with the longterm operation of dual-polarization radar, it is very important to test and correct the inherent deviations of the amplitude and phase caused by the azimuth rotary joint.