The Independent Decomposition And Multiplicative Demodulation Analysis Of The Gravity Tide Signal And The Study Of Anomaly Information

With the accumulation of observations of solid tide and the development of relevant measuring instruments,scientists have found that gravity changes the gravity value of the earth.This change can be well reflected by the observation of the earth’s solid tides.This is the most basic and direct physical amount of the earth’s density change and the geodynamic characteristics under various environments.We find that it changes in time and space through a study of the observations of the gravity tide.Its spatial changes are manifested in the changes in the structure of the crust and upper mantle.However,its change in time has a direct and indirect connection with some catastrophic earthquakes.Therefore,it is possible to find out the corresponding relationship with the natural earthquake through the study of the observation data of the gravity tide.It provides a certain basis for earthquake predictionIn the paper,a model which describes the relation between the independent components of gravity tide signal and the gravity tide effects from the orbit position change of earth,moon and sun is proposed.Using independent component analysis based on a surface-simplex swarm evolution algorithm(SSSE),three independent components are drawn from gravity tide signal.Besides,the multiplicative demodulation of the decomposed independent component is carried out by spectral correlation method.In the paper,a particle surface-simplex search is designed based on particle surface-simplex and particle surface-simplex neighborhood.This is a kind of swarm intelligence optimization algorithm with simple structure.Through the experiment,we verify the feasibility and effectiveness of the algorithm.By this method,the gravity tide is decomposed into several major frequency bands,such as daily wave,half day wave and long period wave and so on.In addition,spectral correlation method is introduced in this paper.It implements the multiplicative demodulation of independent components.Finally,this method is applied to the analysis of the gravity earth tide signal,and the orthogonal decomposition of the gravity earth tide signal is realized,and it corresponds with the orthogonal decomposition model first.In our way,through the observation data analysis in Yunnan area,we find that there is abnormal information in the long periodic wave spectrum during the earthquake.This reflects the precursory anomalies of the earthquake,which may provide a basis for predicting earthquake time and location.The results show that this method is an effective method for the analysis of gravity earth tide signals and the extraction of abnormal information before earthquakes.It provides a new idea for seismic anomaly information identification.