Cyclic Spectrum Analysis Of Gravity Solid Tide Signals

Solid earth tide is a phenomenon of the approximation viscoelastic deformation which produced by the day、the moon and other celestial tidal force act on the whole earth, is also a kind of nonstationary processes. The change of time and space of gravity tide, is not only related with the change of the relative position of earth, the sun, moon, but also related with the change of the lstructure and the stress-strain of the earth’s interior medium. As is known to all, the earth’s rotation cycle, the cycle of the moon around the earth and the earth’s orbital cycles are stable,thus it can be seen that the tidal gravity signal also has a periodic variation, so the tidal gravity signal is a non-stationary signal which has smooth cycle characteristics.Through consulting data and simulation experiments, this paper mainly analyse the concept the nature and the model of the tidal gravity signal,and chose to adapt its research methods based on its smooth cycle characteristics as a non-stationary signal,namely principal component analysis and cyclic spectrum Firstly,compared with the experimental results,this paper calculated and list the main tidal wave frequency value;secondly, describes a orthogonal decomposition mode of the gravity solid tide and selects the 3 road signals with the same longitude and different latitude. The 3 road signals are assessed by using the PCA method in order to get the principal component weights,again with each principal component component as the source signal, respectively, to cyclic spectrum analysis; its results compare with the main tidal wave theory frequency value of the sun and the moon, then obtain the experimental results that namely the principal component analysis and cyclic spectrum analysis are applied to analyze the tidal gravity signal, can arrive at the modulation relationship among geophysical information which correspond to the orthogonal decomposition mode of the gravity solid tide.