Constellation Autonomous Orbit Determination Based On Lunar Libration Point Orbit

With the development of space science and technology, libration points and its nearby orbits and quasi-periodic orbits have been more and more applications. Halo orbit has its unique configuration in the space, and there are differences in the force model between Halo orbit and lunar orbit. In the background of Lunar detection, This paper study the system feasibility of the Lunar-Halo orbit satellite constellation in the situation in the absence of ground support, which may provides a new way for the precise orbit determination in lunar exploration, especially the observation on the back of the moon.Main conclusions of the paper are:1. Stability Index and Linear Stability Order are introduced to judge orbits'stability. The stability of Halo orbit near the L1and L2 point in the Earth-Moon system is analyzed, providing a selected basis of Halo orbit in the Lunar-Halo orbit satellite constellation.2. Analyze the characteristic of force model and configuration in Halo and two-body orbits, and then prove the system observability of the LMO-LL2Halo and LMO-LL1Halo orbit satellites constellations by numerical simulation.3. The selection of Halo orbit has influences in the result of orbit determination. The stability of Halo orbit affects the result. When the Halo orbit is close to the moon, even if the Linear Stability Order is 0, orbit determination results will be affected due to poor structural stability of orbits.4. Regardless of the ranging system bias and velocity observables, the orbit determination accuracy of LMO in the direction of R/T/N are in meter-scale in the statistical observation arc, and the orbit determination accuracy of Halo satellite are better than 20 meters, in which the direction accuracy for both T are worse than the other two directions. The orbit determination accuracy of LMO satellite is better than Halo satellite's. Track extrapolation 15 days, LMO orbit determination accuracy is in meter-scale, and Halo satellite orbit determination accuracy is in 100 m level.5. Using the method of additional prior information can improve the ranging system bias from the characteristics of poor self calibration. When ranging system bias is within 30 meters, the orbit determination accuracy of LMO satellite is in meter-scale in statistical observation arc, and the orbit determination accuracy of Halo satellite is better than 30 meters. Track extrapolation 15 days, the orbit determination accuracy of LMO satellite changes little, remaining in the meter-scale, and the orbit determination of Halo Satellite has great influences by the ranging system bias. The orbit results are better when ranging system bias is smaller. When the ranging system bias is within 10 meters, the determination accuracy of Halo satellite orbit is within 100 meters.6. Combined orbit with distance measurement and velocity measurements for orbit determination can improve precision of orbit determination, when the velocity measurements have certain accuracy. Higher the accuracy of the velocity measurements are, better the orbit determination results are; when the velocity measurements with an accuracy of 1 mm/s, the distance measuring system error has little effect on the orbit results.