CHAMP Gravity Field Recovery Using Energy Conservation Method
XU Tian-he, YANG Yuan-xi
£¨Xi'an Research Institute of Surveying and Mapping, xi'an 710054, China£©
Abstract£ºThe theory and method of CHAMP gravity field recovery using energy conservation method are introduced. The problem related to the accelerometer data is pointed out. The mathematic model and differential arithmetic for calibrating the accelerometer data are presented, which can be used for estimating the scale, bias and bias drift parameter simultaneously and efficiently. Based on 30 days' rapid science orbit and accelerometer data from CHAMP data centre, the 50 degree and order global gravity field model XISM02 is recovered. The XISM02 model is compared to other recent models, EGM96, GRIM5C1, EIGEN1S and EIGEN2. The assessment with the Arctic gravity anomalies data is also made among these models. The result shows that XISM02 as well as EIGEN1S and EIGEN2 yields a good fit to the geopotential field in Arctic area.
Key words£ºearth gravity field model; energy conservation; scale factor; bias parameter