1899.7～1992.0光学观测的极移序列分析  

ON ANALYSIS OF POLAR COORDINATES VARIATION 1899 .7～1992 .0

作　　者：王保卫[1] 顾震年[1] 

机构地区：[1]中国科学院上海天文台,上海20000

出　　处：《中国科学院上海天文台年刊》1999年第20期29-36,共8页Annals Shanghai Astronomical Observatory Chinese Academy of Sciences

摘　　要：利用傅里叶谱分析、数字滤波器、小波变换分析对重新处理的1899．7至1992．0年相对于H37参考系的最新均匀极坐标序列Pole37作了分析，结果表明：（1）Chandler摆动的谱结构在不同的历元处是不同的，在1930年前后的时段确实存在“双峰”结构。在1930年以后Chandler摆动为稳定的单峰，其振幅是随时间变化的。从“双峰”到单峰是一个平稳的“演化”过程。；（2）极移的周年振荡的周期、振幅是较稳定的；（3）从资料分析得到极移的Markowitz项不像一个随机运动，而是一个周期为近30年、振幅为25mas左右的天平动。（4）极移的线性漂移速率在Y分量上比较明显。其X分量为1．6mas／a，Y分量为3．4mas／a，速度方向为西经64°．8，速度大小为3．75mas／a。<Atrstract>By means of the Fourier transform, the Ellip filter and the wavelet transform, a new homageneous set of the polar motion data for the yeare 1899. 7～1992.0, which is newly reduced, has been analysed. The results show:1. The spectrum structure of the Chandler wobble is different for different epochs. There occurs'double peak' around 1930. Only one peak appeared in the Chandler wobble after 1930. The period is stable, but the amplitude varies with time. The transfer from 'double peak' to one peak in the Chandler wobble has a stable evoutionary process.2. Both period and amplitude in the annual period of poler motion is stable.3. The long～period component in the polar motion seems to be a libration wtth the period of neary 30 years, the amplitude 25mas and the trajectory of high ellipticity rather than a random motion.4. The drift in average position is very obvious in the Y-coordinate. The rates are estimaed to be about 1 .6mas/a in X and 3 .4mas/a in the Y. The velocity vector is in a direction of 64. 8 degrees West tongitude with moptude of about 3 .75 mas/a.

关 键 词：钱德勒摆动 资料处理 频谱分析 傅利叶分析 小波变换分析 

分 类 号：P127.4[天文地球—天体测量]