利用函数拟合的低空风切变三维建模与雷达回波仿真

高保真的低空风切变数据是进行低空风切变检测和飞行性能分析的必要基础。为解决低空风切变危险性高、发生突然且持续时间短等带来的真实数据不易获取的难题，本文提出了一种利用函数拟合的低空风切变三维建模方法。该方法依据风切变的流体力学特征，通过函数拟合的方式建立风场类型及特征可变的三维密度场和速度场，并按照现有机载气象雷达在风切变探测模式下的天线扫描与工作方式，实现低空风切变雷达回波仿真。仿真结果表明:该方法可灵活快速地实现低空风切变三维风场建模，雷达回波的速度估计结果较好地反映了低空风切变径向速度沿距离方向呈现反“S”型特征的分布特点。 

The 3D Modeling and Radar Echo Simulation of Low-Altitude Wind Shear Using Function Fitting

The high fidelity data of low-altitude wind shear is the necessary foundation for flight performance analysis and low-altitude wind shear detection. To solve the difficult problem of real data obtainment, which is caused by the characteristics of suddenness, short duration and high hazard, a three-dimensional modeling method of low-altitude wind shear via function fitting is proposed in this paper. On the basis of hydrodynamic characteristics of wind shear, the three-dimensional density and velocity field is simulated by using the function fitting method. Then, according to the scanning process of airborne weather radar, which is under the wind shear detection mode, the radar echo simulation of the low-altitude wind shear is realized. Results of simulation have proved that the method can realize the three-dimensional wind field modeling of low-altitude wind shear flexibly and quickly. The wind speed estimation of echo signals can indicates the relationship between the Doppler velocity and distance which has the distribution characteristics of “S” shape.