基于SGP4模型的卫星多普勒频移补偿方法研究

针对卫星与地面站进行通信时,地面站接收到的信号存在明显的多普勒频移现象,提出了一种基于SGP4模型的卫星多普勒频移补偿算法。首先,根据开普勒定律推导出多普勒频移公式;然后由卫星星历信息,基于SGP4模型预测出卫星的轨道,计算出卫星和地面站之间的相对位置和相对速度,得出多普勒频偏,在地面站分别进行预校正与补偿;最后,使用STK/HPOP生成标称轨道对SGP4模型生成的预测轨道进行误差分析和性能评估。仿真结果表明,对于工作在Ka频段、轨道高度200~1 000 km的低轨卫星,多普勒频偏估计精度优于50 Hz,精度高;随着轨道高度的增加,多普勒频偏估计更加精确。

Research on Doppler Frequency-Shift Compensation Method Based on SGP4 Model in Satellite Communication Systems

When satellites communicate with the ground station, significant Doppler shift is observed by ground-based terminals. A Doppler shift compensation algorithm based on SGP4 model is proposed in this paper. Firstly, According to Kepler's laws, the Doppler shift formula is deduced in this article. Then, based on ephemeris information and SGP4 model to calculate the relative position and the relative velocity between the satellite and the ground station, then calculate the amount of Doppler-shift to complete the pre-correction and compensation by the ground station. At last, the nominal orbit produced by STK/HPOP is used to finish the error analysis and performance evaluation of the orbit predicted by SGP4 model. Simulation result shows that, for LEO satellites that work at Ka-band , whose orbit altitudes are between 200km and 1000km, the Doppler-shift error is less than 50Hz;And the higher the orbital altitude is, the more accurate the Doppler frequency estimation will be.