jgg     2015 35 (2):  356-359    ISSN: 0412-1961  CN: 21-1139/TG Environmental Test and Analysis on Electromagnetic Observation at Yingcheng Geomagnetic Station 1〓Key Laboratory of Earthquake Geodesy, Institute of Seismology, CEA, 40 Hongshance Road, Wuhan 430071, China 2〓Earthquake Administration of Hubei Province, 40 Hongshance Road, Wuhan 430071, China Received: 2014-07-16  Revised: null  Online: 2015-04-15 Supporting info