A statistical analysis of the amplitude of Earth polar shift in time-frequency domain
Abstract
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.
- Publication:
-
Acta Astronomica Sinica
- Pub Date:
- February 2001
- Bibcode:
- 2001AcASn..42...88K
- Keywords:
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- WAVELET TRANSFORM;
- POLAR SHIFT;
- STATISTICAL ANALYSIS;
- PERIOD VARIATION