Landslides caused by open-pit mining are one of the most dangerous geological hazards in China. Displacement of landslides are different from the deformation of ground subsidence due to existing horizontal deformation and vertical deformation at the same time. In this paper, we extend the multi-aperture InSAR method to monitor large-scale horizontal deformation of landslides. And then, we integrate the multiple-aperture InSAR and traditional differential SAR interferometry (D-InSAR) to reveal deformation field distribution of landslides caused by open-pit mining. The results demonstrated that the proposed procedure is effective to monitor large-scale horizontal deformation and vertical deformation of landslides, especially for the north-south direction landslides.

The ionosphere is a dynamic system with complex structures. With the development of abundant global navigation satellite systems, the ionospheric electron density in different altitudes and its time variations can be obtained by ionospheric tomography technique using GNSS observations collected by the continuously operating GNSS tracking stations distributed over globe. However, it is difficult to represent and analyze global and local ionospheric electron density variations in three-dimensional (3D) space due to its complex structures. In this paper, we introduce a grid-based system to overcome this constraint. First, we give the principles, algorithms and procedures of GNSS-based ionospheric tomography technique. Then, the earth system spatial grid (ESSG) based on the spheroid degenerated octree grid (SDOG) is introduced in detail. Finally, more than 400 continuously operating GNSS receivers from the International GNSS Service are utilized to realize global ionospheric tomography, and then the ESSG is used to organize and express the tomography results in 4D, including 3 spatial dimensions and time.