轨道速度

To understand the hyperbolic motion of the probe and give necessary orbit information not only the discrete positions to both ground-base or satellite autonomy device, we studied the variation of hyperbolic orbit and gave the variation equations like that of elliptic orbit.

这段轨道相比其它段虽然很短，但却是实现最终探测目标的关键弧段。为了更好地了解探测器的在这一关键弧段的运行状态，给地面测控系统或是星上自主设备提供必要的轨道信息，而不仅仅是探测器在一些孤立点上的位置和速度，有必要对双曲线轨道及其变化特征进行研究，给出类似于椭圆轨道及其变化的一些基本规律。

Firstly, This paper processes geometry filtration based on character of orbit's apogee and perigee after orbit model is analyzed and based. Secondly Space Debris is separated into two kinds, coplanar and not coplanar according as location interrelation of target and debris. In Dynamic filtration's processing, considering prediction time limit and orbit perturbation, secular effects which have increaser effect is considered so that some need catching danger time point is appeased, some law about time when target and debris pass intersectant line each other is inferred, when debris and object are in different plane and some similar law also is inferred otherwise. The time list is arithmetical progression. These laws can improve calculation efficiency remarkably; Lastly orbit predict is a course approaching least distance. Danger time point in the last step become beginning time point from which debris and object's position and velocity are calculated by SXP4 Model which is an analytic model.By result, determine that relative movement trend is closer or apart, farther calculate the interval apart from time when predictive least relative distance occurs. Least relative distance and time when least distance occurs is calculated finally. It is a fast approach course adopting varied interval.

本文在分析、建立轨道摄动计算模型的基础上，首先采用基于轨道远、近地点特征对大量编目在册的空间碎片进行初步几何静态筛选，然后根据碎片与目标轨道面的相对位置特点把碎片分为异面与准共面两种情况以进行动态筛选，在筛选过程中考虑到预报时限长度和轨道摄动影响，引入了轨道摄动中具有积累效应的长期项以满足危险时间点的捕捉要求，利用了长期项摄动变化线性的特点导出了碎片与目标异面情况下各自过交线的时间序列成准等差数列的规律性和准共面情况下类似的规律性，从而显著地提高了前期轨道筛选的计算效率；最后对剩余危险碎片和目标飞行器利用SXP4轨道预报模型在前期轨道筛选的基础上以各个危险探测时间点为预报的时间起点，并根据预报计算结果，分析目标和碎片在该时间点的运动趋势是相互远离还是相互接近，推出预计最小相对距离发生时刻相对此刻的时间长度，得到其随时间变化的局部最小相对距离以及危险距离发生的时刻和相对速度，这是一个采用变时间步长、快速逼近最小相对距离的过程。

With the development of track traffic, the deformation and destruction of track system is speeded up consequently. The major reason of track invalidation is the track vibration.

随着我国轨道交通的不断发展，列车运行速度不断提高，轨道系统振动的强度也随之增加，从而加速了轨道系统的变形和破坏。

The analytical method is always used due to the large amount of the objects and not very high accuracy of forecasting. A method based on the position and velocity derived from the mean orbit elements directly is given, which is to avoid the problem of singularity in calculating the periodic terms of orbit elements variation, thus the process and software can be simplified.

在已有分析法得到t时刻平均根数的基础上给出一种轨道预报方法，由t时刻的平均根数给出该时刻卫星的位置和速度，在此基础上将地球非球形引力摄动的周期项直接用卫星直角坐标的位置和速度分量表示，这样可以避免在计算轨道根数变化的周期项时出现的奇点问题，从而对根数的选择无特殊要求，可适用于各种轨道，简化预报程序和相应的软件，提高预报效率。

The line that passes through the center of the Earth linking the perigee and apogee, known as the line of apsides, itself rotates in the orbital plane at a speed that depends on the geometry of the elliptical orbit and the inclination of the orbital plane to the equator.

经过地球中心，连接近地点和远地点的线称为apside线，卫星在轨道平面上以某个速度旋转，这个旋转速度根据椭圆轨道以及轨道平面到赤道的倾角的几何学来计算。

When the disturbing potential of 1m2/s2 accuracy, or the approximate velocity of accuracy less 2mm/s in the formula of the rotation of the gravity potential is required, the satellite orbit data not satisfied the potential rotation computing demand are rejected from the GFZs Rapid Science Orbit and TUMs ReducedDynamic Orbit. If the disturbing potential is desired 05m2/s2 at satellite track, the satellite velocity required in formula of the rotation of the gravity potential should be recomputed or the GFZs Postprocessed Science Orbit is adopted.

当要求在卫星轨迹处获得1m2/s2精度的扰动位时，也即要求位旋转效应公式中卫星速度的近似精度小于2mm/s时，GFZ的快速科学轨道、TUM的约化动力法轨道只需要剔除那些速度精度不满足要求的卫星轨迹点；当要求在卫星轨迹处获得05m2/s2精度的扰动位时，应当重新估算上述轨道的速度信息，或采用精度更高的GFZ事后科学轨道。

So he compiled data on more than 20,000 stars from existing sky surveys whose position in our galaxy and orbital velocity had been accurately measured.

这样，他从现有的天空观测资料中搜集到20，000多颗恒星的资料。这些恒星都位于我们银河系，对它们的轨道速度已经有过精确地测量。

As the vehicle climbs, the engines are aligned with the flight directional axis of the vehicle, and remain in this position until orbital velocity is achieved.

作为汽车爬升，引擎，是不结盟，与飞行方向轴的车辆，并停留在这一立场，直到轨道速度的实现。

He based this relationship, using astronomical parameters calculated that each of their counterparts in Gua stars the average orbital velocity and density values were a secret.

他依据这个关系，利用天文参数进行计算，证明出每一对应卦位所属星体的平均轨道速度和密度均分别为一个密值。

The combinations, and movements, of these masses with gravitational, centrifugal and orbital velocity vector forces, create what we call the equatorial bulge, and thus, the axis of figure.

具有重力，离心力和轨道速度的矢量力的质量结合与运动，引起了我们所谓的赤道区鼓起，而就是形状轴。

And Pharaoh spoke to Joseph, saying, Your father and your brothers have come to you.

47：5 法老对约瑟说，你父亲和你弟兄们到你这里来了。

Additionally, the approximate flattening of surface strip using lines linking midpoints on perpendicular lines between geodesic curves and the unconditional extreme value method are discussed.

提出了用测地线方程、曲面上两点间短程线来计算膜结构曲面测地线的方法，同时，采用测地线间垂线的中点连线和用无约束极值法进行空间条状曲面近似展开的分析。