jgg     2014 34 (5):  134-138    ISSN: 0412-1961  CN: 21-1139/TG SIMULATION OF GRAVITY GRADIENT DATA AND ITS  APPLICATIONS ON INERTIAL NAVIGATION 1)School of Geodesy and Geomatics，Wuhan University，Wuhan 430079 2)Tianjin Institute Geotecnical Investigation & Surveying，Tianjin 300191 Received: 2014-01-10  Revised: null  Online: 2014-09-26 Supporting info