Results 241 to 250 of about 14,054 (271)
Some of the next articles are maybe not open access.
Bulletin Geodesique, 1982
Based on an analysis of polar motion behavior, we found the possibility of predicting polar motion up to one year in advance. Comparing these predicted polar coordinates with the observed ones (smoothed), the rms of the differences is about 0".02. The differences of the relative polar motion are much smaller.
exaly +2 more sources
Based on an analysis of polar motion behavior, we found the possibility of predicting polar motion up to one year in advance. Comparing these predicted polar coordinates with the observed ones (smoothed), the rms of the differences is about 0".02. The differences of the relative polar motion are much smaller.
exaly +2 more sources
Selecting data for autoregressive modeling in polar motion prediction
Acta Geodaetica Et Geophysica, 2019The Least-squares extrapolation of harmonic models and autoregressive (LS + AR) prediction is currently considered to be one of the best prediction model for polar motion parameters. In this method, LS fitting residuals are treated as data to train an AR model. But it is readily known that using too many data will result in learning a badly relevant AR
Guobin Chang +2 more
exaly +2 more sources
Long-term polar motion prediction using normal time–frequency transform [PDF]
Journal of Geodesy, 2013 This paper presents normal time–frequency transform (NTFT) application in harmonic/quasi-harmonic signal prediction. Particularly, we use the normal wavelet transform (a special NTFT) to make long-term polar motion prediction. Instantaneous frequency, phase and amplitude of Chandler wobble, prograde and retrograde annual wobbles of Earth’s polar motion
Lintao Liu, Guocheng Wang
exaly +2 more sources
Journal of Geodesy, 2004
Short-term forecast of the polar motion is considered by introducing a prediction model for the excitation function that drives the polar motion dynamics. The excitation function model consists of a slowly varying trend, periodic modes with annual and several sub-annual frequencies (down to the 13.6-day fortnightly tidal period), and a transient decay ...
T.M. Chin, R.S. Gross, J.O. Dickey
exaly +2 more sources
Short-term forecast of the polar motion is considered by introducing a prediction model for the excitation function that drives the polar motion dynamics. The excitation function model consists of a slowly varying trend, periodic modes with annual and several sub-annual frequencies (down to the 13.6-day fortnightly tidal period), and a transient decay ...
T.M. Chin, R.S. Gross, J.O. Dickey
exaly +2 more sources
Multi-parameter Polar Motion Prediction Based on Effective Angular Momentum Function
Chinese Astronomy and Astrophysics, 2022ZHAO Xin +4 more
exaly +2 more sources
El Niño Impact on Polar Motion Prediction Errors
Studia Geophysica et Geodaetica, 2001The polar motion prediction is computed as a least-squares extrapolation of the polar motion data. The least-squares model consists of a Chandler circle with constant or variable amplitude, annual and semiannual ellipses, and a bias. The model with constant amplitude of the Chandler oscillation is fit to the last three years of polar motion data and ...
W. Kosek, D.D. McCarthy, B.J. Luzum
openaire +1 more source
Polar motion modeling, analysis, and prediction with time dependent harmonic coefficients
Journal of Geodesy, 2008A time dependent amplitude model was proposed for the analysis and prediction of polar motion time series. The formulation was implemented to analyze part of the new combined solution, EOP (IERS) C 04, daily polar motion time series of 14 years length using a statistical model with first order autoregressive disturbances. A new solution approach, where
H Baki Iz
exaly +2 more sources
Prediction of Polar Motion by Least-Squares Collocation
1990In this paper a procedure for predicting of pole positions using the least squares collocation approach is presented. Predicted pole coordinates are needed for a nearly “real-time” positioning. The main purpose of this work was to elaborate an efficient algorithm to evaluate x,y coordinates of the future pole positions, which would be as close as ...
Roman Galas, Rudolf Sigl
openaire +1 more source
Polar motion prediction based on adaptive filtering of variable forgetting factor
2017 Forum on Cooperative Positioning and Service (CPGPS）, 2017The Polar Motion (PM) is the important parameter of Earth Rotation Parameters (ERP), and the high-precision prediction of PM plays a key role in the applications of autonomous orbit determination, the geodetic survey, navigation and aviation. In this paper, a modified algorithm is proposed to improve the PM prediction accuracy based on combination of ...
Tianhe Xu
exaly +2 more sources