机载前视风切变雷达是飞机进行风切变探测和预警的重要工具. 为了设计一种可输出风切变雷达仿真信号的风切变信号发生器, 利用快速傅立叶变换( FFT) 法分析某型机载前视风切变雷达的回
波信号, 分别用频谱估计法和经典功率谱估计法两种方法估计了雷达回波信号的多普勒频移, 比较两种方法的优劣, 进而选择经典功率谱估计法计算出风场的径向风速分布. 建立均一化静止对称的风场模型
仿真了风切变雷达的回波信号, 从而设计出可输出风切变雷达仿真信号的风切变信号发生器, 可满足机载气象雷达航空部附件维护和维修时对便携性和灵活性的需求.
Abstract
Airborne weather radar is important for detecting low altitude wind shear which is a major contributing factor in many airline crashes. Numerous accidents have occurred that were attributed to low?altitude wind shear,
Research on the wind shear detection for airborne forward looking wind shear weather radar has important application value. Up to now, several methods have been proposed for wind shear signal processing, such as fast
Fourier transform, pulse pair processing and so on. In industry, the most widely used method is fast fourier transform, so fast fourier transform is the chosen method for analyzing airborne forward looking wind shear radar
simulated echo data. T he spectrum estimation method and the classical power spectrum estimation method are used to estimate the Doppler frequency. The results obtained by these two methods are compared, and the classical power
spectrum estimation method is better because its result contains more spectral information. The classical power spectrum estimation method is chosen to calculate the radial velocity of the wind field. According to this method, the
weather radar simulated echo data is analyzed, the potential danger of wind shear can be well reflected in the result, and the radial velocity field is estimated. The result shows that the average radial velocity experienced a dramatic
change, the slope of the average radial velocity curve can be used to measure the danger of wind shear. Thehomogenization static symmetric wind field model is established for simulating the wind shear radar echo data. The
model can reflect the characteristics of the radial velocity in wind shear field. According to the model, a wind shear radar signal generator is designed, based on the simulated radar echo data which is easy to modify the parameters on
demand. The generator can load the simulated radar echo data from personal computer, and output signals to the radio frequency( RF) simulator. The generator can meet the airborne weather radar，s requirements for portability and flexibility.
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脚注
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基金
毫米波国家重点实验室( K200819)
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