摘要
分析了１９７９年８月至１９９６年１月之间由ＭａｒｋⅢＶＬＢＩ时延资料得到的ＩＡＵ１９８０章动模型在经度（δψ）和交角（δε）方向的偏移序列，得到了对ＩＡＵ１９８０章动模型中主项系数的改正，并检测了自由地核章动。计算步骤依照常规资料处理方法设计，并采用了一些分析技巧以便充分利用资料的整个时段和减小端部效应对参数解的影响。对拟合残差序列的进一步分析表明，自由地核章动是统计显著的，但其参数尤其是其振幅可能具有时变性质，表现为在经度和交角方向自１９８６至１９９５年的持续减弱。
お?Observations of the IAU 1980 nutation daily offsets in longitude (δ△ψ) and obliquity (δ△ε) from Mark Ⅲ VLBI delay data between Aug. 1979 and Jan. 1996 are analyzed for the corrections to coefficients of the largest IAU 1980 nutation terms and for the detection of the free core nutation. The computation is designed for the following general data processing algorithm with skills adopted for a possible best use of the whole data span and a reduction of the edge effect of data series on solutions. Further analysis of the post-fit residuals suggests that the free core nutation is statistically significant and its parameters may be characterized by time-variation, especially for the amplitude, which was decreasing from 1986 to 1995 for both δ△ψ and δ△ε. Geophysical explanation is still leaving unknown.
出处
《云南天文台台刊》
CSCD
1998年第2期33-34,共2页
Publications of the Yunnan Observatoty
