Simulation of Complex Meteorological Target Echoes for Airborne Dual-Polarization Weather Radar Based on Invariant Imbedding T -Matrix

This article presents a simulation method for complex meteorological target echoes in airborne dual-polarization weather radar based on the invariant imbedding T-matrix (IITM) method. The approach integrates IITM with the weather research and forecasting (WRF) model. Initially, meteorological scenes are modeled and simulated using WRF. This is followed by the modeling of six meteorological targets: raindrops, snow, hail, graupel, ice crystals, and cloud droplets, taking into account their possible varying shapes and setting proportional distributions for these shapes in the simulation. Subsequently, the complex refractive indices of these meteorological targets are calculated using the Debye model, Polder-van Santern (P-S) equivalent medium model, and melting ratio model. These indices are then incorporated with IITM to compute the scattering amplitude matrices for targets of various shapes. The final stage involves calculating the reflectivity factors of the six types of meteorological targets under different shape ratios. These factors are then applied to the radar meteorological equation to determine the echo power. The covariance matrix, illustrating the pulse correlation within the echo signal, is formulated using meteorological target echo power and wind speed data. This matrix undergoes Cholesky decomposition to facilitate the simulation of echo signals from meteorological targets for airborne dual-polarization weather radar. The simulation results indicate that the method can accurately replicate meteorological features, with comparative analysis against actual measurement data further validating the method's effectiveness and reliability.