基于“天问一号”数据的自主火星重力场构建

Martian gravity field recovery based on the Tianwen-1 mission data

“天问一号”是中国首次自主火星探测任务,一次实现了对火星的环绕、着陆、巡视探测.火星物理场与内部结构研究是“天问一号”任务设定的五大科学目标之一,本文先回顾了国内外在火星重力场方面研究的新进展.为探究“天问一号”当前轨道对火星重力场解算贡献,本文开展了仿真1年的“天问一号”任务轨道跟踪数据对基于3个月300 km圆极轨道跟踪数据解算火星重力场的贡献.结果表明,加入“天问一号”数据对极轨道数据解算的火星重力场方面的改进主要表现在2–10阶次和35–45阶次,另外还发现大偏心率轨道和数据增多有助于降低火星重力场低阶次模型误差.进一步地,本文还处理了“天问一号”近4个月的实际射电跟踪数据(2022年07月至2022年11月),解算得到1个10阶次自主火星重力场模型.这对后续火星基础模型的研究,特别是自主火星重力场的构建,具有一定参考意义.

Tianwen-1 is the first independent Chinese interplanetary exploration mission that has realized orbiting,landing,and roving on Mars.Research of the physical field and internal structure of Mars is one of the five major scientific objectives of the Tianwen-1 mission,playing a significant role.Based on the successful orbiting,landing,and roving of Tianwen-1,this paper systematically reviews the domestic as well as international research progress of the Martian gravity field solution and expounds on the relevant theoretical methods of Martian gravity field inversion.With regard to exploring the applicability of the Chinese Martian gravity field solution based on the orbital data obtained from the Tianwen-1 normal mission stage,the question regarding the contribution of the Tianwen-1 mission to the low polar orbit data was addressed for the first time.Moreover,we confirmed that the incorporation of the Tianwen-1 data improved the polar orbit data in the degree of 2–10 and 35–45.Furthermore,a 10-degree Martian gravity field model is solved using the recently obtained three-month data.