基于GNSS的高轨卫星定位技术研究

Research on Positioning of High Earth Orbital Satellite Using GNSS

利用全球卫星导航系统(GNSS)进行导航定位具有全球、全天候、实时和高精度的优点,应用于高地球轨道(HEO)卫星的定位,能够提供精确的轨道和姿态确定,并且可以克服目前主要利用地面测控系统对HEO卫星进行定位的设备复杂、投资高等缺点,使得自主导航成为可能.本文对利用GNSS的高轨卫星定位相关技术进行了研究,分析了单一GNSS系统和多个GNSS组合系统的卫星可见性、动态性和几何精度因子(GDOP).通过仿真分析表明,利用组合GNSS系统并通过提高GNSS接收机灵敏度的方法,可以解决GNSS进行HEO卫星定位的相关问题,并能保证HEO卫星定位精度的要求.

The GNSS as a navigation and positioning method has global, all-weather, real time and high precision characteristics. Using it on the high earth orbital satellites in positioning can provide precise orbit and attitude determination, overcome the disadvantage of complex equipment and high cost which using ground measurement and control system to positioning, make it possible to autonomous navigation. New and exciting opportunities become possible if satellites are able to autonomously determine their own orbit. For example, precise onboard orbit determination opens the door to satellites flying in formation. However, receivers in low Earth orbit have virtually the same view of the navigation satellite constellation as receivers on the ground. But satellites orbiting at geostationary altitudes and higher have a severely limited view of the main beams of the GNSS satellites. The main beams are either directed away from these high-altitude satellites or they blocked to a large extent by the Earth. So, using much weaker signals is a fundamental requirement for a high orbital altitude GNSS receiver, but it is certainly not the only challenge. Other unique characteristic of this application must also be considered. On the one hand, dynamic characteristics will be more different at high Earth orbit. High dynamic situation makes it difficult to use weaker signals. On the other hand, Position Dilution of Precision （PDOP） figures are much more higher at geostationary and higher altitudes because visible navigation satellites are concentrated in a much smaller region with respect to the spacecraft antenna. Spacecraft navigation receiver must be designed to withstand a variety of extreme environmental conditions. In this paper, positioning of high earth orbital satellites using GNSS is researched. The visibility of navigation satellites, dynamic characteristics, Geometric dilution of precision are analyzed using single GNSS and integrated GNSS. Through simulation and analyzing, it is verified that using GNSS can realize the positioning of HEO satellite and obtain enough positioning precision requirement.