Precise orbit determination for representative near-Earth asteroids based on optical observations of ground-based stations and the Earth-Moon L1 point’s orbit

Precise orbit determination of near-Earth asteroids (NEAs) provides a critical foundation for exploration missions. Considering that cislunar space is a critical domain for future human space activities and the unique positional advantage of the Earth-Moon L1 point, space-based optical observations from the Earth-Moon L1 point’s orbit hold significant potential for improving NEAs orbit determination accuracy. Coordinating such space-based observations with ground-based optical observations is expected to provide essential technical support for high-precision orbit determination. This study focused on two representative NEAs, 2016HO3 and Apophis. We validated the effectiveness of existing optical observations by processing 328 latest ground-based data of 2016HO3. The calculated position true error of the initial state vector was 31.932 km, with a position uncertainty of 24.293 km. The Yarkovsky effect parameter A2 of 2016HO3 was solved to be (−1.257 ± 0.343)×10−13 AU/day2. Furthermore, we conducted ground-space based orbit determination simulation analyses for 2016HO3 and Apophis to quantitatively evaluate the potential advantages of combining optical observations from the Earth-Moon L1 point’s orbit with ground-based observations in enhancing orbit determination accuracy. The results indicate that within the observation accuracy considered in this study, space-based optical observations reduce orbit determination uncertainty by up to 20% for 2016HO3 and 62% for Apophis. The inclusion of space-based observations reduces the position true error by up to 50% for 2016HO3 and 83% for Apophis, and it can enhance the signal-to-noise ratio (SNR) of A2. Additionally, we found that the orbit error of the L1 point probe has a notable influence on the position true error of NEAs, reaching several kilometers for 2016HO3 and several hundred meters for Apophis.