A Spectrum-Reconstruction Based I/Q Series Simulator for Dual-Polarization Weather Radar

Significant non-Gaussian characteristics are observed in echo signal spectra during severe convective weather. Current weather radar simulators, typically based on Gaussian spectrum assumptions, are difficult to validate non-Gaussian spectra signal processing algorithms. This paper proposes a simulator capable of generating arbitrarily shaped echo spectra by reconstructing the power spectra from meteorological particle microphysical information. Within each radar resolution volume (RRV), sub-grids are created, and WRF model outputs are interpolated onto these grids. The T-matrix method computes microphysical properties—including aspect ratios and orientation distributions—for rain, snow, ice, and graupel particles. A particle terminal velocity model maps particle diameter to radial velocity, enabling calculation of each velocity bin's contribution to the Doppler spectrum per sub-grid. Sub-grid spectra are then integrated using antenna pattern weighting to form the overall Doppler spectrum and power spectral density for the RRV, from which IQ data are generated. The simulator is validated using stratospheric typhoon observations, demonstrating its effectiveness. It offers a physically consistent simulation framework for developing and testing non-Gaussian spectra processors in severe convective weather and supports flexible radar scenario configuration.