College of Geoexploration Science and Technology Jilin University Changchun 130021 China;
College of Geoexploration Science and Technology Jilin University Changchun 130021 China;
College of Geoexploration Science and Technology Jilin University Changchun 130021 China;
China Aero Geophysical Survey and Remote Sensing center for Land and Resources Beijing 100083 China;