基于轨道根数的低轨卫星轨道预测算法

Prediction algorithm of close-orbit satellite based on orbit elements

光电设备因太阳夹角变化、轨道遮挡等原因无法对卫星进行自动跟踪时,需要对卫星轨道进行预测。本文针对利用卫星轨道根数进行轨道预报时难以同时满足实时性和精度要求的问题,提出了一种新的基于轨道根数的卫星轨道预测方法。分析了卫星轨道的运行规律,根据低轨卫星的运行特点,利用椭圆曲线对卫星轨道进行预测,并对卫星轨道的轨道方程进行了近似处理。通过引入一些冗余变量简化了卫星轨道解算模型,在保证计算实时性的前提下,大大提高了轨道预测精度。实验显示:采用线性外推方法对卫星轨道进行预测时,预测5s后,轨道预测的偏差会增大到10″,而采用本文提出的基于轨道根数的卫星轨道预测算法,预测50s后的最大预测偏差均不超过2″,极大地提高了卫星轨道预测精度,实现了光电设备在无法对卫星进行自动跟踪时,能够对卫星进行"盲跟踪"。

When a photoelectric device can not track the satellite due to the changed intersection angle of the sun or the orbit blocking,the satellite orbits have to be predicted.Because the traditional orbit prediction method based on orbit elements can not meet the requirements of real-time and precision measurement simultaneously,this paper proposes a new satellite orbit prediction method based on orbit elements.The movement rule of satellite orbits was analyzed,then the elliptic curves were used to predict the satellite orbits and to process approximately the orbit equation based on the characteristics of a low orbit satellite.Some redundancy variable quantities were induced to simplify the calculation model for satellite orbit,so that the orbit prediction accuracy is greatly increased in guaranteeing a good real-time calculation.The experiments show that when the linear extrapolation is used to predict the satellite orbit,its prediction deviation will increase to 10″after 5sforecasting.However,if the method presented in this paper based on the orbit elements is used in the prediction,the maximum deviation is not more than 2″after 50 sprediction.The method has greatly promoted the prediction precision of satellite orbit,and makes the photoelectric device implement the＇blind tracking＇for satelliteswhen the automatic tracking is become to be invalid.