Analysis of Undifferenced Kinematic POD for LEOs Using TriP

In this paper,zero-difference kinematic precise orbit determnation method is adapted for GRACE by using TriP software.Considering the effect of data quality,some observational data of GRACE were solved to obtain appropnate catoff elevation and weighting stategy.Using the optimal strategy,we processed four months observational data of GRACE and compared the orbits with the products provided by JPL.The results indicate that the accuracy of orbit determnation of TriP reaches 5-6 cm,which is at the same level of national and international studies.