Abstract: Since the accuracy of the solved north-south displacements with the traditional method of fusing multi-track InSAR observations is quite poor, it is challenging to scientifically identify the risks of geohazards of open-pit mine slopes. To circumvent this, we propose a new method to monitor three-dimensional displacements of open-pit mine slopes with multi-track InSAR by incorporating an aspect constraint in this paper. Firstly, a prior constraint is constructed based on the prior knowledge that the slope in open-pit mine horizontally moves towards the aspect direction in theory. Then, a functional model involving the prior constraint and three-dimensional displacements of open-pit mine slope is created, according to the projection of three-dimensional displacements onto SAR line of sight direction. Thirdly, three-dimensional displacements of open-pit mine slopes are solved based on the function model. The proposed method is tested in Xinqiu open-pit mine area, in China, and the results show that the accuracy of three-dimensional displacements is about 1.2 cm, occupying 5.6% of the maximum displacement. The proposed method is beneficial to improve the accuracy of InSAR-based three-dimensional displacements of open-pit mine, and further to enhance the ability to identify potential landslides in open-pit mine slope.

Key words: InSAR, open-pit mine, 3D deformation, aspect constraint, rainfall