高精度天体引潮力计算中需要考虑地球扁率的影响.由DE421历表计算得到太阳系各个天体在GCRS中的坐标,基于天球参考系经典的岁差章动转换方法、IERS 2010规范推荐的转换参数以及IERS发布的EOP 08C04数据模型,在综合考虑影响天体坐标转换的各种因素(框架偏差、岁差、章动、地球自转、时间尺度转换、极移)改正后,得到天体在ITRS中的坐标,并由此计算得到1962年至2015年间地球扁率对各天体引潮力位和引潮力影响的具体数值.计算结果表明:地球扁率对天体引潮力的影响,对月球来说不超过1.8898×10~(-11) ms~(-2)(1.8898 nGal),对太阳来说不超过0.0018×10~(-11) ms_(-2)(0.0018nGal),对其他天体来说可完全忽略不计.地球扁率对月球、太阳引潮力影响的变化周期与相应天体的运行周期一致.
The effect of earth's flattening must be considered when calculating the high-precision tidal generating force of celestial bodies.In this paper,the coordinates of celestial bodies of solar system in GCRS were calculated based on DE421,these coordinates were transformed to ITRS through celestial reference system equinox-based precession-nutation transformation method,parameters recommended by IERS Conventions(2010)and the EOP 08 C04 model provided by IERS,including celestial reference frame bias,precession,nutation,earth rotation,the difference between TT and UT1,polar motion,et al.The numerical values of tidal generating potential and tidal generating force are calculated based on the basic formulas.The results indicate that between 1962and2015 the earth's flattening effect on moon's tidal generating force doesn't exceed 1.8898×10~(-11) ms~(-2)(1.8898nGal),and that effect on sun doesn't exceed 0.0018×10~(-11) ms(-2)(0.0018nGal),and that effect on other celestial bodies can completely be neglected.The results also indicated that the period of effect of the tidal generating force by moon and sun was consistent with the corresponding celestial bodies' period.