jgg     2008 28 (5):  100-104    ISSN: 0412-1961  CN: 21-1139/TG ANALYSIS OF EFFECT OF f -3 TERM AND MAPPING FUNCTION ON IONOSPHERIC DELAY Zheng Lei; Chen Kai; Li Zhenghang ; and Zhu Heng School of Geodesy and Geomatics, Wuhan University, Wuhan\ 430079 Received: 1900-01-01  Revised: 1900-01-01  Online: null Supporting info null