A simulation and analysis of the observation errors of cloud intensity and structure with the S-band phased array radar and the CINRAD/SA

The State Key Laboratory of Severe Weather of CAMS and Nanjing Research Institute of Electronics Technology have jointly developed the first Sband phased array weather radar of China. In order to reduce the radar scan cycle, the Sband phased array weather radar uses a transmitted beam wider in pitch and narrower in azimuth, and multireceived beams to overlap the transmitted beam. However, when using this scanning method, beam width and gain are changed with elevation. For the wider beam width, it reduced the radar resolution, resulting in the absence of the details of radar echo. In order to explain theoretically the difference between observed cloud intensities and structures by the SBand Phased array radar and the CINRAD/SA, a high spatial resolution cloud dataset is reconstructed by using the bilinear interpolation method. And we also simulate the features of the SBand phased array weather radar and CINRAD/SA to scan the cloud and thus obtain the reflectivity based on which the difference of the scanning features for the Sband phased array radar and the CINRAD/SA is analysed. The results show that the echo structure has been, to some extent changed because of the horizontal and vertical smoothing of the phased array radar which weakened the center of echo intensity with the center of some small strong echoes disappearing. Compared with the SA radar, it reduced very weak echo dimensions and the strong echo area, and increased the area of echoes of intermediate intensity. The paper suggested the method of contrasting the CINRAD and the phased array weather radar, and provided a theoretical framework for the calibration of this phased array weather radar and the quantitative measurements.