伽利略卫星的等势面和正常重力场

给出了轨道面接近赤道面的轨旋同步卫星的正常重力场在等势面上分布的展开式，并讨论了潮汐对其正常重力场的影响，利用这一方法，讨论了伽利略卫星正常重力场及其在等势面上的分布，以及木星的潮汐对伽利略卫星的正常重力场的影响，计算表明，潮汐对伽利略卫星的正常重力场影响不大，其径向的影响grt大约是10^-3-10^-5m/s^2的量级，与重力场在经度和纬度方向的分量接近，通过估算，月球的重力场所受到的潮汐影响要比绝大多数伽利略卫星受到的潮汐影响小。

Equipotential Surface and Normal Gravity of the Galilean Satellites

In this article, expanded equations of normal gravity on the equipotential surface is proposed for a natural orbit synchronous satellite whose orbital plane is close to its equatorial plane. Tidal effects on the normal gravity are also discussed. The authors apply these to the Galilean satellites. Calculations suggests that tides raised by Jupiter weakly affect the Galilean satellites. The radial displacements of the gravity due to tides raised by Jupiter are in the range between 10-3ms-2 and 10-5ms-2, which are similar to the latitudinal and longitudinal displacements. Especially, the variations along the latitude circle are larger than those along the longitude circle. It can be concluded from estimates that tidal effects on most of the Galilean satellites are larger than that on the Moon.