1. Chongqing College of Electronic Engineering, Chongqing 401331, China
2. Technology Innovation Center of Geohazards Automatic Monitoring, Ministry of Natural Resources, Chongqing Institute of Geology and Mineral Resources, Chongqing 401120, China
3. Beijing Urban Construction Survey, Design and Research Institute Co. Ltd., Beijing 100101, China
4. China Coal Science and Engineering Group Chongqing Research Institute Co. Ltd., Chongqing 400039, China