Contributions of Chinese VLBI Network to the Low Degree Coefficients of the Jupiter Gravity Field

With the advancement of deep space exploration, the research focus gradually shifts from earth moon and terrestrial planets, such as Mars and Mercury, to gaseous planets. In the Jupiter exploration mission, the development of the precise orbit determination software is an important tool for simulation at the mission planning and processing the radio tracking data during task implementation. It is an important scientific problem to solve the Jupiter gravity field model and the rotation orientation model. We developed a software named as Jupiter gravity recovery and analysis software (JUPGREAS) with independent intellectual property rights. In order to cross-validate check, we compared the results of orbit propagation and precise orbit determination (POD) with the well-known software GEODYN-II (geodetic parameter estimation and precision orbit determination system-II). The difference of the orbital prediction is at 10^-4 m after 7 days. For POD, the position difference is about 1.84 m under the white noise of 1 mm/s. Meanwhile, we analyzed the Jupiter gravity field recovering with the help of the data from Chinese VLBI (very long baseline interferometry) network (CVN). Gaussian white noise of 0.5 ns and 0.5 mm/s is added to the VLBI delay and the two-way Doppler observation, respectively. It is found that the VLBI delay data from CVN could improve the accuracy of the harmonic coefficients of the Jupiter gravity field and the orbital errors is about 0.822 m.