Jupiter gravity field model estimation based on precision orbit determination of Juno spacecraft

Jupiter’s gravity field is the main data source for studying its internal structure. Currently, the determination of Jupiter’s gravity field mainly relies on the orbital tracking data from NASA’s Juno mission. China has planned the “Tianwen-IV” mission, which aims to explore the Jupiter system, with one of its main scientific objectives being the acquisition of Jupiter’s gravity field. To this end, this study develops a precise orbit determination and gravity field estimation software platform for the Jupiter spacecraft. Using the real measurement data of the Juno spacecraft from 2016 to 2018, a gravity field model and tidal Love numbers of Jupiter were derived based on precise orbit determination. The results indicate that, using Ka-band data from the mid-phase of the Juno mission, a 20th-degree Jupiter gravity field model was successfully estimated autonomously, revealing the zonal circulation features and north-south asymmetry of Jupiter’s gravity field. Additionally, a unified tidal response model was used to solve for Jupiter’s 4th-degree tidal Love numbers. The derived gravity field model was also used for precise orbit determination of the Juno spacecraft, with results matching the accuracy of those published by the Juno team. This work provides an important reference for China’s upcoming “Tianwen-IV” Jupiter exploration mission.