Quantitative Impacts of Different Polarization Operating Modes and Waveforms on Weather Observables for Polarimetric Phased Array Radar

One of the significant challenges in using polarimetric phased array radars (PPARs) for weather observations is the implementation of dual polarization with an acceptable level of cross-polar isolation induced by the antenna. This article quantitatively analyses and compares the bias caused by cross-coupling in different modes. For the alternately transmitting and simultaneously receiving (ATSR) mode, simultaneously transmitting and simultaneously receiving (STSR) mode, and the pulse-to-pulse phase coding STSR (PC-STSR) mode, the bias is quantified as a function of the maximum cross-polar power, while for the alternate orthogonal waveform STSR (A-OW-STSR) mode, the bias is a function of the maximum cross-polar power and waveform isolation. In the meantime, the cross-polar isolation required in different modes to attain the accuracy of polarization and spectral moment parameters measurement is quantitatively analyzed. The results from theoretical developments and simulation analysis exhibit that the A-OW-STSR mode can obtain an unbiased estimate of velocity and have an equal requirement for cross-polar isolation as the PC-STSR mode. In addition, the A-OW-STSR mode can not only obtain the polarization scattering matrix (PSM) of the target within one pulse repetition time but also ensure accurate precipitation observation. Therefore, it can be used as an alternative transmitting mode for multifunction PPAR.