中低轨卫星高仰角时刻的轨道预测

使用改进的拉普拉斯算法对人造卫星进行轨道预测时,在卫星仰角过高及卫星过顶点时刻其外推精度都较低,无法满足轨道预测的精度要求。本文基于对外推数据和实测数据的分析,提出了基于时间校正的轨道预测方法。该方法首先对外推数据和实测数据进行坐标旋转,然后用实测数据对外推数据进行时间校正,从而获得高精度的卫星轨道预测数据。利用水平式光电设备对卫星进行了跟踪实验。实验中使用了大于60s时长的高精度自动跟踪数据,先进行运动方程的拟合,然后进行时间校正,外推出了超过20s时长的高精度预测数据,且在卫星过顶点时刻,预测偏差可以保持在3″左右。实验结果表明,该方法有效地提高了卫星在高仰角时刻的轨道预测精度和保精度跟踪时间。

Orbit forecast of medium and low orbit satellite at the time of high elevation

When the improved Laplace algorithm is used to forecast the satellites' orbit, the extrapolate accuracy of the algorithm is usually relatively lower at a high elevation angle for the satellite, especially at the time of passing zenith. To meet the requirements of high-precision orbit forecast, this paper proposes a new orbit forecast method based on time-correction by analysis of extrapolating data and measured data. Firstly, the method performs a coordinate rotation for the extrapolating data and measured data, Then, it uses the measured data to correct extrapolation data on the time to obtain high-precision forecast data of satellite orbit. An experiment is carried out by using a horizontal photoelectric device with high-precision automatic tracking data more than 60 s length. By fitting the equations of motion and time correction, over 20 s duration precision forecast data are extrapolated, and the forecast error has be maintained at about 3" on the time of passing zenith. Experimental results show that this method effectively improves the orbit forecast accuracy and the time ensuring tracking accuracy when the satellite is at the time of high evelation angle.