1. Institute of Geophysics and Geomatics; China University of Geosciences; Wuhan 430074 Hubei China
2. Institute of Geophysics; Chengdu University of Technology; Chengdu 610059 Sichuan China
3. China railway Eryuan Engineering Group Co. Ltd; Chengdu 610031 Sichuan China
4. State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, College of Information Engineering; Chengdu University of Technology; Chengdu 610059 Sichuan China