Dual polarization upgrade and identity evaluation of Shanghai weather radar

In 2014, Shanghai WSR-88D radar was upgraded from single polarization to dual polarization system. The paper firstly provides an overview of Shanghai WSR-88D radar system and meaning of dual polarization. For dual polarization radar, the most significant modifications are equally splitting transmitter powers by RF PALLET, installing AME box which includes two channel receivers and testing module, replacing antenna rotary joint, adding vertical waveguide and replacing feed-horn. Performance of weather radar system directly influences data quality. The stability and identity of two transmitter and receiver channels are very important for system evaluation. By extracting parameters from system and analyzing the curve of key parameters in the whole Sep, 2014, the paper illustrates imbalance of Peak power, noise level and noise temperature, and analyses the reason that caused abnormity. Radial interference or outside noise in one polarized direction will degrade performance of one channel and influence data quality of weather products.