Improvement of instantaneous positioning by spatial stacking and modified sidereal filteri

Improvement of instantaneous positioning by spatial stacking and modified sidereal filtering methods with application to the 2008 Ms8.0

Wenchuan earthquake

Liu Gang，Li Gang，Tan Kai，Nie Zhaosheng，Zhou Yu and Jia Zhige 【摘 要】Abstract:We obtained several displacement time series from the Sichuan permanent GPS net and processed the 1-Hz data observed during a few days before the 2008 Ms8.0 Wenchuan earthquake by double-difference instantaneous positioning technique.We filtered the data by the spatial stacking and the modified sidereal filtering methods to reduce correlation bias in space and time.The results indicate that these methods can improve the precision significantly. 【期刊名称】大地测量与地球动力学（英文版） 【年(卷),期】2012(003)001 【总页数】6

【关键词】Key words:1-Hz GPS;spatial stacking;modified sidereal filtering;Ms8.0 Wenchuan earthquake; deformation

1 Introduction

High sampling-rate GPS data may reveal rapid crustal deformation during an earthquake［1，2］.Combined with static GPS data they may provide strong constraints for inverting the earthquake-related slip distribution and history［3-5］，thus making the application of high