A new method for deriving broad-band polar motion geodetic excitations  

作　　者：Wei Chen Jiesi Luo Jim Ray Jiancheng Li 

机构地区：[1]Hubei Luojia Laboratory,School of Geodesy and Geomatics,Wuhan University,Wuhan 430079,China [2]National Oceanic and Atmospheric Administration,Silver Spring,MD,USA [3]Central South University,Changsha 410083,China

出　　处：《Geodesy and Geodynamics》2024年第5期453-464,共12页大地测量与地球动力学（英文版）

基　　金：supported by the National Natural Science Foundation of China(grant numbers 41874025 and 41474022)。

摘　　要：While the geodetic excitationχ(t)of polar motion p(t)is essential to improve our understanding of global mass redistributions and relative motions with respect to the terrestrial frame,the widely adopted method to deriveχ(t)from p(t)has biases in both amplitude and phase responses.This study has developed a new simple but more accurate method based on the combination of the frequency-and time-domain Liouville's equation(FTLE).The FTLE method has been validated not only with 6-h sampled synthetic excitation series but also with daily and 6-h sampled polar motion measurements as well asχ(t)produced by the interactive webpage tool of the International Earth Rotation and Reference Systems Service(IERS).Numerical comparisons demonstrate thatχ(t)derived from the FTLE method has superior performances in both the time and frequency domains with respect to that obtained from the widely adopted method or the IERS webpage tool,provided that the input p(t)series has a length around or more than 25 years,which presents no practical limitations since the necessary polar motion data are readily available.The FTLE code is provided in the form of Mat Lab function.

关 键 词：Earth rotation Polar motion Geodetic excitation Liouville's equation Mat Lab 

分 类 号：P127.4[天文地球—天体测量] P228[天文地球—天文学]