基于单频星载GPS数据的低轨卫星精密定轨

为满足搭载单频GPS接收机低轨卫星的精密定轨需求以及深化单频定轨研究，文中解决了单频星载GPS数据的周跳探测问题，并利用“海洋二号”（HY-2A）卫星及“资源三号”（ZY-3）卫星的单频星载GPS实测数据采用两种方法确定了二者的简化动力学轨道，并通过观测值残差分析、与双频精密轨道比较、激光测卫数据检核等方法对所得轨道精度进行评定。结果表明，在不考虑电离层延迟影响的情况下，HY-2A卫星定轨精度为2~3dm，ZY-3卫星为1m左右；而采用半和改正组合消除电离层延迟一阶项影响后，二者定轨精度均显著提高，HY-2A卫星三维精度提高至1dm左右，ZY-3卫星提高至1~2dm。文章的研究成果表明，搭载单频GPS接收机的低轨卫星也可获得厘米级的定轨精度。

Precise Orbit Determination for LEO Satellites Using Single-frequency GPS Observations

To meet the need for precise orbit determination POD of the LEO satellites equipped with a single-frequency SF GPS receiver and deepen the research on POD with SF GPS data, the problem of cycle-slip detection for SF GPS data was solved, and the reduced-dynamic orbits for HY-2A satellite and ZY-3 satellite were determinated with two different approaches using the SF GPS observations. The precision of the derived orbits was assessed by the analysis of the observation residuals, comparison with the precise orbits derived from dual-frequency (DF) GPS data and validation with satellite laser ranging SLR measurements. The results indicate that the 3D precision of the SF orbit without ionospheric delay correction is between 2dm and 3dm for HY-2A and about 1m for ZY-3, and the notable improvement with the group and phase ionospheric correction GRAPHIC observation is achieved to eliminate the first order ionospheric delay and the 3D precision can reach 1dm for HY-2A and 1～2dm for ZY-3. The results demonstrate that the sub decimeter level accuracy can be achieved for POD of LEO equipped with a SF GPS receiver.