极移振幅和相位的时—频域统计分析

极移的各种周期变化与地球上的许多现象，如地震等，有某种紧密的联系。研究这些周期变化及其成因是相当重要的。利用新的观点来分析这 一经典问题。首先将复小波变换引入极移的研究之中，了解极移的复小波变换及各种周期变化。提出小波变换对数幅相图的概念，并对小波变换的振幅和相位的变化分别进行了分析。结果表明：极移的模值以及小波变换的模值都有某种周期的变化。小波变换尺度比较小时，可以描述短周期的变化；小波变换尺度大时可以描述较长周期的变化。

A STATISTICAL ANALYSIS OF THE AMPLITUDE OF EARTH POLAR SHIFT IN TIME-FREQUENCY DOMAIN

Various periodic variations of the polar shift are closely related with many phenomena on the earth, for example the earthquake. It is important to study these periodic variations and the cause of their origin. The authors make a fresh look at this classic problem. The complex wavelet transform is employed to study the variation of the polar shift in this paper. This transform and various periodic variations are discussed. The logarithmic amplitude phase map of complex wavelet transform is put forward. The variation of amplitude and phase of complex wavelet transform is analyzed. The results show that the model of polar shift and its complex number wavelet transform have some periodic variation.It describes the short-term periodic variation in small scale and the long-term variation in large scale.