A Unified Formulation of Polarimetric Weather Radar With Application to IQ Data Simulation

Abstract

The meteorological parameters derived from polarimetric weather radar measurements are of interest for nowcasting and to feed numerical models for forecasting. The accuracy of the derived meteorological parameters is affected by the polarimetric measurement scheme considered as well as by the system hardware (e.g., the antenna radiation patterns or receive channels imbalances). However, determining the accuracy of the estimated meteorological parameters is difficult since no ground truth is available. This fact has motivated the development of weather radar data simulators that allow comparison of the assumed weather parameters used to feed the system and the finally estimated weather parameters. In this paper, the weather radar model is reviewed. A unified formulation applicable to all polarimetric measurement systems is developed. This formulation shows that antenna effects can be decoupled from scattering effects. Based on this formulation, a weather radar simulator is proposed. This radar simulator does not require the fine sampling in the elevation and azimuth directions required by previous simulators. Therefore, the computational load and execution times are significantly reduced. Finally, it is important to point out that the radar simulator proposed provides as much fidelity to the actual radar system as previous simulators.