jgg     2011 31 (6):  11-14    ISSN: 0412-1961  CN: 21-1139/TG IONOSPHERIC ANOMALY DETECTION BEFORE JAPAN Ms9.0 EARTHQUAKE BY USE OF IONOSPHERIC TOMOGRAPHY TECHNOLOGY Chen Biyan; Dai Wujiao; Cai Changsheng; Kuang Cuilin; and Liu Ying Department of Geomatics Engineering, Central South University, Changsha 410083 Received: 1900-01-01  Revised: 1900-01-01  Online: null Supporting info null