Study On Geophysical Information Based On PCA Extraction Of Gravity Solid Tide Signals

Solid earth tide is a cyclical deformation phenomenon generated by solid earth under the action of sun, the moon and other celestial bodies tide-generating force, which is a kind of nonstationary processes. The gravity solid tide is gravity changes on the surface of the rigid earth caused by the tidal power. The research work of gravity solid tide signal analysis is of great significance, which lays a good foundation not only for the study of the earth’s interior structure and the physical information, but also has a positive impact for seismic research.Principal component analysis is that the all original variables are transformed into the new variables,which are principal component. At the same time,the new variables are not correlative each other. They as much as possible to include the original variable information. In fact, the main idea of principal component analysis is decorrelation and dimension reduction. The method of principal component analysis in dealing with multi variables problem, will reduce computation and reduce the complexity of analysis problem. Because of its advantages, PCA has been widely used.This paper proposes a orthogonal decomposition model of tidal gravity signal, it is decomposed into two orthogonal directions of component, including the component of the Earth’s rotation axis direction and the component of the Earth’s equatorial plane direction. It deals with the gravity solid tide signal based on PCA to decorrelation and obtain the corresponding frequency components. The result is consistent with the orthogonal decomposition model of gravity solid tide signal. The obtained frequencies have better relationship with the theoretical frequencies. So they have a clear physical meaning. The paper provides a new way of thinking for tidal gravity signal analysis and processing.