The Improved Sidereal Filtering of Time Series Considering Segments’Similarity in Coseismic Displacement

Based on the traditional sidereal filtering method,an improved sidereal filtering method is put forward,accounting for segments’similarity,namely before building filtering operator.Firstly determine the segments’ similarity of the coordinates time series between earthquake day and before that day or after that day,and then based on the similarity measure index to identify weight of each day for filtering.Different similarity measure indicators are analyzed.After that the universal image quality index(UIQI)method is recommended as the similarity measure for the improved sidereal filtering.It’s more scientific and reasonable than other similarity measure which considers the correlation coefficient between two series,own mean value and variance as well.The results show that the improved sidereal filtering can effectively improve the single epoch positioning accuracy and reliability,completely overcome the defects of traditional filtering method,is beneficial to batch processing without manual intervention.