针对在地面站天线对空间站观测任务中,通常基于卫星工具包(satellite tool kit,STK)软件规划出天线对空间站的方位角和俯仰角,实现天线对空间站的自动跟踪.为了保证天线跟踪的准确性和可靠性,需要定期计算出准确的空间站轨道和天线的方...针对在地面站天线对空间站观测任务中,通常基于卫星工具包(satellite tool kit,STK)软件规划出天线对空间站的方位角和俯仰角,实现天线对空间站的自动跟踪.为了保证天线跟踪的准确性和可靠性,需要定期计算出准确的空间站轨道和天线的方位俯仰角,并更新规划任务.因此科学分析与评估空间站两行轨道根数(two line elements,TLE)长期预报精度,对地面站实现空间站的精准跟踪具有重要意义.本文以中国空间站(China Space Station,CSS)梦天实验舱为例,基于TLE数据,利用STK软件提供的简化常规摄动规模型(simplified general perturbations4,SGP4)模型计算空间站轨道以及空间站相对于西安地面站的方位角和俯仰角,并分析不同策略下的精度效果.试验结果表明:在第二天更新空间站的TLE,可以获得较好的轨道结果,从而更好地保障天线的跟踪精度.展开更多
The high speed of low earth orbit(LEO) satellites makes the terminals at each beam tend to switch rapidly and frequently.The predictable trajectories of LEO satellites allow for predictable terminal switching,therefor...The high speed of low earth orbit(LEO) satellites makes the terminals at each beam tend to switch rapidly and frequently.The predictable trajectories of LEO satellites allow for predictable terminal switching,therefore a simple and highly accurate orbit prediction model is required to swiftly obtain accurate switching time.This study utilizes the simplified general perturbations(Version 4)(SGP4) model to predict the LEO satellite trajectory of WT-1,an LEO satellite developed independently by the 54th Research Institute of China Electronics Technology Group Corporation(CETC).The obtained prediction results are compared with the actual telemetry data of the WT-1,which gives the accuracy of the SGP4 predicted satellite trajectory within 1 km.The terminal entry/exit beam timing is simulated by using the SGP4 model-predicted orbit and the satellite' s own telemetry data.The simulation result shows that the error between the SGP4 model-predicted terminal entry/exit beam timing and the actual timing is less than 1 s.The influence of terminal motion on prediction is discussed.The results show that the error caused by the movement of the ground terminal on the prediction is less than 0.687 s,and the SGP4 model has a definitely practical value for terminal switching determination in the LEO constellation.展开更多
双行根数(Two Line Element,TLE)作为一类广泛使用的空间物体编目数据,其预报精度和误差特性是TLE编目在空间碎片研究中所要关注的问题之一.TLE编目需要配合SGP4/SDP4(Simplified General Perturbations 4/Simplified Deep Space 4)模...双行根数(Two Line Element,TLE)作为一类广泛使用的空间物体编目数据,其预报精度和误差特性是TLE编目在空间碎片研究中所要关注的问题之一.TLE编目需要配合SGP4/SDP4(Simplified General Perturbations 4/Simplified Deep Space 4)模型进行轨道预报,对深空物体来说,主要考虑带谐项J_(2)、J_(3)、J_(4)摄动、第三体日月摄动和特殊轨道共振问题修正等.其中,SGP4/SDP4模型第三体摄动计算时,对日月轨道近似采用了长期进动根数和简单平运动的方式,在外推10 d时存在约2◦–3◦的日月位置偏差.日月轨道计算可选用更加精确的方法来改进初始位置估计,并根据日月运动规律的不同,对太阳轨道采用平运动近似,对月球轨道采用计算真近点角近似,在外推10 d时,二者位置偏差可分别减小到约1′–2′和15′–20′范围.采用激光测距卫星Etalon 1、伽利略卫星导航系统Galileo 23卫星作为对比算例,结果分析表明二者原始的TLE编目轨道进行预报时存在明显的位置误差异常变化趋势;采用日月轨道计算改进后,重新定轨得到的“改进”编目具有更加精确的轨道预报结果.展开更多
文摘针对在地面站天线对空间站观测任务中,通常基于卫星工具包(satellite tool kit,STK)软件规划出天线对空间站的方位角和俯仰角,实现天线对空间站的自动跟踪.为了保证天线跟踪的准确性和可靠性,需要定期计算出准确的空间站轨道和天线的方位俯仰角,并更新规划任务.因此科学分析与评估空间站两行轨道根数(two line elements,TLE)长期预报精度,对地面站实现空间站的精准跟踪具有重要意义.本文以中国空间站(China Space Station,CSS)梦天实验舱为例,基于TLE数据,利用STK软件提供的简化常规摄动规模型(simplified general perturbations4,SGP4)模型计算空间站轨道以及空间站相对于西安地面站的方位角和俯仰角,并分析不同策略下的精度效果.试验结果表明:在第二天更新空间站的TLE,可以获得较好的轨道结果,从而更好地保障天线的跟踪精度.
文摘The high speed of low earth orbit(LEO) satellites makes the terminals at each beam tend to switch rapidly and frequently.The predictable trajectories of LEO satellites allow for predictable terminal switching,therefore a simple and highly accurate orbit prediction model is required to swiftly obtain accurate switching time.This study utilizes the simplified general perturbations(Version 4)(SGP4) model to predict the LEO satellite trajectory of WT-1,an LEO satellite developed independently by the 54th Research Institute of China Electronics Technology Group Corporation(CETC).The obtained prediction results are compared with the actual telemetry data of the WT-1,which gives the accuracy of the SGP4 predicted satellite trajectory within 1 km.The terminal entry/exit beam timing is simulated by using the SGP4 model-predicted orbit and the satellite' s own telemetry data.The simulation result shows that the error between the SGP4 model-predicted terminal entry/exit beam timing and the actual timing is less than 1 s.The influence of terminal motion on prediction is discussed.The results show that the error caused by the movement of the ground terminal on the prediction is less than 0.687 s,and the SGP4 model has a definitely practical value for terminal switching determination in the LEO constellation.
文摘双行根数(Two Line Element,TLE)作为一类广泛使用的空间物体编目数据,其预报精度和误差特性是TLE编目在空间碎片研究中所要关注的问题之一.TLE编目需要配合SGP4/SDP4(Simplified General Perturbations 4/Simplified Deep Space 4)模型进行轨道预报,对深空物体来说,主要考虑带谐项J_(2)、J_(3)、J_(4)摄动、第三体日月摄动和特殊轨道共振问题修正等.其中,SGP4/SDP4模型第三体摄动计算时,对日月轨道近似采用了长期进动根数和简单平运动的方式,在外推10 d时存在约2◦–3◦的日月位置偏差.日月轨道计算可选用更加精确的方法来改进初始位置估计,并根据日月运动规律的不同,对太阳轨道采用平运动近似,对月球轨道采用计算真近点角近似,在外推10 d时,二者位置偏差可分别减小到约1′–2′和15′–20′范围.采用激光测距卫星Etalon 1、伽利略卫星导航系统Galileo 23卫星作为对比算例,结果分析表明二者原始的TLE编目轨道进行预报时存在明显的位置误差异常变化趋势;采用日月轨道计算改进后,重新定轨得到的“改进”编目具有更加精确的轨道预报结果.
