基于FFT与CZT的高精度测角方法

High-precision Angle Measurement Method Based on FFT and CZT

对均匀线阵雷达,通过快速傅立叶变换(Fast Fourier Transform,FFT)来实现数字波束形成(Digital Beam Forming,DBF)的快速运算,可以得到同时多波束的效果,根据峰值所在的波束确定目标初始角度。在初始角度附近感兴趣的区间内采用CZT(Chirp-Z Transform)方法来细化频谱,根据细化后谱峰位置确定目标角度。该方法可以在较小FFT点数的情况下有效提高角度计算精度,降低对系统存储资源的需求,适合应用于车载雷达等对系统成本敏感的阵列雷达系统中。

For uniform linear array radar, Through fast Fourier transform(FFT) to realize the fast operation of digital beam forming(DBF), the effect of simultaneous multi beam can be obtained, and the initial angle of the target can be determined according to the beam where the peak is located. CZT is used in the interval of interest near the initial angle(Chirp-Z transform) method to refine the spectrum and determine the target angle according to the position of the refined spectrum peak. This method can effectively improve the angle calculation accuracy and reduce the demand for system storage resources in the case of small FFT points. It is suitable for vehicle radar and other array radar systems sensitive to system cost.