基于1962至2022年极移观测值的时序分析及长期预报研究  

Time-Series Analysis and Long-Term Prediction Based on Polar Motion Observations from 1962 to 2022

作　　者：魏二虎[1] 李岩林 白小宇 王广渠 刘经南[2] WEI Erhu;LI Yanlin;BAI Xiaoyu;WANG Guangqu;LIU J ingnan(School of Geodesy and Geomatics,Wuhan University,Wuhan 430079,China;GNSS Research Center,Wuhan University,Wuhan 430079,China)

机构地区：[1]武汉大学测绘学院,湖北武汉430079 [2]武汉大学卫星导航定位技术研究中心,湖北武汉430079

出　　处：《测绘地理信息》2024年第1期29-35,共7页Journal of Geomatics

基　　金：国家重点研发计划(2018YFC1503600);国家自然科学基金(42374015)。

摘　　要：极移参数(polar motion,PM)是地球定向参数(earth orientation parameter,EOP)的重要组成部分,在天文大地测量、卫星的导航定位以及卫星的自主定轨等领域有重要的应用。本文首先利用国际地球自转服务(international earth rotation and reference systems service,IERS)提供的极移观测值进行极移时间序列频谱分析及周期项的提取。结果表明,快速傅里叶变换与离散傅里叶变换周期项提取到的周期项基本无差异,但极移X、Y分量时变分析结果存在差异。此外,本文将正弦逼近应用到极移参数的预报,对于长时间尺度的极移参数预报最小二乘外推模型效果最佳,但预报模型精度易受到周期项提取结果的影响;最小二乘外推模型在极移正向预报和反推拟合效果相近,借助正弦逼近方法可以一定程度上增强模型拟合效果。上述研究结果可为地球自转参数的预报研究提供参考。Polar motion(PM)is an important component of the earth orientation parameter(EOP),which has important applications in astronomical geodesy,navigation and position⁃ing of satellites,and autonomous satellite orbiting.This study analyzes the spectrum of polar motion time series and extracts the period term via the polar motion observations provided by the international earth rotation and reference systems service(IERS).The results show no difference between the periodic terms extracted by the fast Fourier transform and the discrete Fourier transform periodic terms.Still,there are differences in the results of the time-varying analysis of the polar motion X and Y components.In addition,the least-squares extrapola⁃tion model has the best results for long-timescale polar motion parameter forecasting.The accuracy of the prediction model is easily affected by the period-term extraction results.The least-squares extrapolation model has similar results in the for⁃ward and backward polar motion prediction,and the model fit⁃ting effect can be somewhat enhanced by the sinusoidal ap⁃proximation method.The results of the above study can pro⁃vide important references for forecasting Earth rotation param⁃eters.

关 键 词：极移 时变性 周期项 物理成因 长期预报 

分 类 号：P228[天文地球—大地测量学与测量工程] P128[天文地球—测绘科学与技术]