潮汐现象与同步卫星的姿态稳定性

通讯同步卫星不仅要在精确的同步轨道上运行，还要求其天线必须永远面向地球，具有稳定的运行姿态．本文先将地球视为表面被一层海水全部覆盖的均匀球体，并在地心参照系中分别分析太阳、月亮对海水的作用力．利用万有引力定律求出分别引起太阳潮和太阴潮的潮汐力，得出月亮、太阳引力场的不均匀性是引起潮汐现象的主要原因．然后在质心系中通过对通讯同步卫星系统进行受力分析，并利用类似潮汐现象的引力的不均匀性解释如何保持同步卫星的姿态稳定性。

Tide and attitude stabilization of synchronous satellite

The communications synchronous satellite should move exact synchronous track and it's aerial should be suit to the needs of the earth,while keeping attitude stabilization. The article supposes that the earth is a uniform ball which is surrounded by the seawater, analyzes the force of the sun and the moon to seawater in the earth's core reference frame, calculates the tide force causing the sun tide and the moon tide by the law of gravity, and draw a conclusion that asymmetry gravitation causing the tide is the main reason. The article analyzes that the force act to the communications synchronous satellite in the centroid reference frame, and explains how to retain it's attitude stabilization by asymmetry gravitation causing the tide.