jgg     2015 35 (5):  861-865    ISSN: 0412-1961  CN: 21-1139/TG Sensitivity Analysis of Low-Low Track Gravity Satellite Inter-Satellite  Range Rate to Regional Mass Anomaly 1 Xi’an Research Institute of Surveying and Mapping, 1 Mid-Yanta Road, Xi’an 710054, China 2 State Key Laboratory of Geo-Information Engineering, 1 Mid-Yanta Road, Xi’an 710054, China 3 Technical Division of Surveying and Mapping, 36 Xiying Road, Xi’an 710054, China Received: 2014-08-28  Revised: null  Online: 2015-10-10 Supporting info