傅立叶相位分析导风技术的适用范围和相位重叠分析

本文利用傅立叶相位分析法对示踪云进行频域波谱分析，通过谐波的相位变化计算波速，从而导出云迹风(Cloud Motion Wind—CMW)。本文研究表明，对于给定的导风云图序列，如果示踪云在给定时间间隔内的位移小于两个像距，适用傅立叶相位分析法计算云迹风；否则，在用傅立叶相位分析法计算波速时由于高次谐波出现相位重叠，从而使计算的波速小于实际风速，此时适用最大相关系数法。

THE APPLICATION CONDITION OF FOURIER ANALYSIS TECHNIQUE AND THE ANALYSIS OF PHRASE OVERLAP

Fourier analysis on sequential satellite images is different from maximum correlation technique, it analyses wave spectrum and gets wave speed by computing phrase shift. Studies in this article show that if the displacement of target cloud is less than two pixels, Fourier analysis technique is an appropriate method of computing CMW. In the other case, if the displacement of target cloud is more than two pixels, Fourier analysis technique is not appropriate because of phrase overlap and in this case maximum correlation technique should be adopted.