首页|Estimation of free core nutation parameters and availability of computing options

Estimation of free core nutation parameters and availability of computing options

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  • 国家科技期刊平台
  • NETL
  • NSTL
  • 万方数据
  • 维普
The Earth's Free Core Nutation(FCN)causes Earth tides and forced nutation with frequencies close to the FCN that exhibit resonance effects.High-precision superconducting gravimeter(SG)and very long baseline interferometry(VLBI)provide good observation techniques for detecting the FCN parameters.However,some choices in data processing and solution procedures increase the uncertainty of the FCN parameters.In this study,we analyzed the differences and the effectiveness of weight function and ocean tide corrections in the FCN parameter detection using synthetic data,SG data from thirty-one stations,and the 10 celestial pole offset(CPO)series.The results show that significant discrepancies are caused by different computing options for a single SG station.The stacking method,which results in a variation of 0.24-5 sidereal days(SDs)in the FCN period(T)and 103-104 in the quality factor(Q)due to the selection of the weighting function and the ocean tide model(OTM),can effectively suppress this influence.The statistical analysis results of synthetic data shows that although different weight choices,while adjusting the proportion of diurnal tidal waves involved,do not significantly improve the accuracy of fitted FCN parameters from gravity observations.The study evaluated a series of OTMs using the loading correction efficiency.The fitting of FCN parameters can be improved by selecting the mean of appropriate OTMs based on the evaluation results.Through the estimation of the FCN parameters based on the forced nutation,it was found that the weight function P1 is more suitable than others,and different CPO series(after 2009)resulted in a difference of 0.4 SDs in the T and of 103 in the Q.We estimated the FCN pa-rameters for SG(T=430.4±1.5 SDs and Q=1.52 × 104±2.5 × 103)and for VLBI(T=429.8±0.7 SDs,Q=1.88 × 104±2.1 × 103).

Free core nutationSuperconducting gravimeterVery long baseline interferometryWeight functionOcean tide model

Weiwei Yang、Xiaoming Cui、Jianqiao Xu、Qingchao Liu、Ming Qin

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State Key Laboratory of Geodesy and Earth's Dynamics,Innovation Academy for Precision Measurement Science and Technology,Chinese Academy of Sciences,Wuhan 430077,China

University of Chinese Academy of Sciences,Beijing 100049,China

Hubei Luojia Laboratory,Wuhan 430079,China

Open Fund of Hubei Luojia LaboratoryStrategic Priority Research Program of Chinese Academy of SciencesNational Natural Science Foundation of ChinaNational Natural Science Foundation of ChinaNational Natural Science Foundation of ChinaNational Natural Science Foundation of ChinaYoung Topnotch Talent Cultivation Program of Hubei Province

220100033XDB4100000042174108418740944219253542242015

2024

10.1016/j.geog.2023.05.004

大地测量与地球动力学(英文版)
中国地震局地震研究所

大地测量与地球动力学(英文版)

EI
影响因子：0.568
ISSN：1674-9847
年,卷(期)：2024.15(1)
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