星下点轨迹

星下点轨迹为∞字形同步卫星轨道的实现及应用

Design and application of synchronous orbit with ground track of "∞"

该套软件根据卫星轨道调整前后的轨道参数特点和轨道调整后的星下点轨迹要求，确定机动时间，将调整轨道半长轴与微调星下点轨迹结合起来，在最短时间内完成轨道调整任务。

The software determines maneuver time by considering the adjustment of semi-major axis and ground track .

基于OpenGL的卫星星下点轨迹可视化仿真

Visual Simulation of the Track of Sub-Satellite Point by Using OpenGL

针对J2项摄动的LEO卫星与地面站通信链路，提出一种由偏近点角的超越方程计算时间窗口的新方法，采用以大圆近似星下点轨迹的方法求解此方程。

A transcendental equation about the eccentric anomaly is proposed to compute the time windows between the J2 perturbed LEO satellite and the ground station , and this equation is solved by using the great circle to locally approximate the ground trace .

算法利用大圆弧近似可视窗口内的星下点轨迹获得可见性结果。

The great circle arc is used to approximate the sub-satellite track within the visibility window .

使用等距墨卡托投影，将卫星的星下点轨迹绘制在地球平面图上。

The track of sub-satellite points are drawn on the ichnography of the earth with the projection of Mercator .

轨道维持的任务是将卫星的星下点轨迹保持在设计的参考轨迹附近。

The ground tracks of satellites required for mission should be maintained close to those of reference orbits over the lifetime of satellites .

实现了在全球卫星影像地图上卫星的星下点轨迹的绘制和显示，以及覆盖区域的显示；

Realize the render and display of subastral point tracks on the global satellite images . Also include the display of satellite coverage ;

阐述了基本轨道应用分析理论，包括星下点轨迹计算、可见性分析、覆盖评估和轨道寿命估算。

Expatiated on the application theory of basic orbit , including subastral point calculation , visibility analysis , coverage evaluating and spacecraft life-span estimate .

以轨道半径和轨道倾角为未知量依据星下点轨迹要求条件构建了非线性方程组，但直接求解过于复杂，采取迭代的方法解决。

Non-linear equations are ( constructed ) with the restriction of the satellite ground trace to resolve the unknown semi-axis and inclination , but it 's too complicated to be resolved directly .

快速算法通过分析中继卫星与客户星通信链路的几何特性建立了三类可视球冠模型，采用以大圆近似星下点轨迹的方法计算时间窗口。

In the fast algorithm , the models of three types of visibility spherical caps are established by analyzing the communication links between the relay satellites and the user satellites . By using the circle locally approximation to the ground trace , the time windows are estimated .