利用1985～2010年VLBI数据进行日长变化分析

On Length of Day with 1985-2010 VLBI Observations

摘要: 处理了1985～2010年的VLBI观测数据,提取了日长变化信息,分析了其内符合精度和外符合精度;通过傅立叶分析以及小波分析得出了日长变化的半月周期、月周期、半年周期、周年周期以及更长周期;利用解算出的日长变化信息绘制日长变化积分曲线,分析日长的季节性变化和长期变化,并分析了日长变化因素。

Abstract: The analysis of ΔLOD is of profound significance on climate forecasting,disaster prevention,deep space exploration,geodesy and other fields.With extremely high precision and angular resolution,VLBI plays the irreplaceable role on the analysis of the changes of the length of day.Based on this,the ΔLOD sequence and its precision are estimated from VLBI observations during 1985-2010 with comparison with the results published by IVS.The half-month,month,half-year,year periods and longer periods of the changes of ΔLOD is extracted with FFT and wavelet analysis.At the same time,the integration curve map of the ΔLOD is made to analyze the seasonal and long-term changes of earth rotation.At last,the causes of the changes of LOD are analyzed.