1. Institute of Geophysical and Geochemical Exploration, Chinese Academy of Geological Sciences, Langfang 065000, China
2. National Center for Geological Exploration Technology, Langfang 065000, China
3. Key Laboratory of Geophysical Electromagnetic Probing Technologies, Ministry of Natural Resources, Langfang 065000, China
4. Terrestrial Geophysical Research Center, China Geological Survey, Langfang 065000, China
5. Geophysical Survey Center, China Geological Survey, Langfang 065000, China