傅里叶级数拟合LEO轨道误差下的BDS/GPS/LEO 精密单点定位

针对目前多数低轨道地球卫星(LEO)设计处于初步论证阶段，LEO轨道无法精确获取，轨道误差难以准确表述的问题，提出了一种傅里叶级数拟合LEO轨道误差下的BDS/GPS/LEO 精密单点定位(PPP)分析方法. 该方法根据LEO精密定轨后的轨道误差呈现准周期正弦特性，利用傅里叶级数拟合LEO轨道误差，并仿真生成LEO观测数据和星历产品，分析了LEO轨道误差对BDS/GPS/LEO PPP精度与收敛时间影响. 仿真结果表明:BDS/GPS/LEO PPP定位误差随着LEO轨道误差的增加而逐渐增大，但与测站纬度和LEO星座构型无明显关联. 且为保证全球区域BDS/GPS/LEO PPP收敛时间均短于BDS/GPS PPP收敛时间，引入6×10、12×10、18×10 LEO星座后，其LEO轨道误差均方根(RMS)应小于5 cm、11 cm、12 cm. 

BDS/GPS/LEO precise point positioning based on fourier series fitting LEO orbit error

In view of the problems that most of the low earth orbit (LEO) constellation designs are in the preliminary demonstration stage, the LEO orbit cannot be accurately obtained, and the orbit error is difficult to express accurately, BDS /GPS/LEO precise point positioning (PPP) based on Fourier series fitting LEO orbit error is proposed. Since the orbit error presents a quasi-periodic sinusoidal characteristic, the Fourier series is used to fit the LEO orbit error, and the LEO observation data and ephemeris products are generated by simulation. Finally, the influence of LEO orbit error on the accuracy and convergence time of BDS/GPS/LEO PPP is analyzed. The simulation results show that the BDS/GPS/LEO PPP error increases gradually with the increase of the LEO orbit error, but it is not significantly related to the station latitude and the LEO constellation configuration. And in order to ensure the convergence time of BDS/GPS/LEO PPP in the global area shorter than that of BDS/GPS PPP, the root mean square (RMS) of the LEO orbit error should be less than 5 cm, 11 cm, 12 cm in the 6×10,12×10,18×10 LEO constellation configuration respectively.