Abstract: This paper presents a weight-determining method based on high-precision GPS constraints.In this method,the precision of the multi-LOS D-InSAR deformation observations is evaluated based on the high-precision GPS deformation observations in the same period.Then,considering the influence of system errors and accidental errors on the deformation of a pixel observed by the multi-LOS D-InSAR,a combined fitting model associated with the positions and elevations of a pixel is built.Finally,the precision of deformation from the multi-LOS D-InSAR is evaluated pixel by pixel use the built model,thus determining the weights of observations in the model for resolving three-dimensional surface deformation by the multi-LOS D-InSAR.Authors verify the feasibility and precision of the weight-determining method respectively through a real data experiment based on the case of 2009 L'Aquila earthquake.The results of verification show that the weight-determining method based on high-precision GPS constraints in this article provides reliability for the resolved three-dimensional surface deformation.

Key words: multi-LOS D-InSAR, weight matrix, three-dimensional surface deformation, L'aquila earthquake