Results 131 to 140 of about 20,578 (146)
Some of the next articles are maybe not open access.
Short-term prediction of UT1-UTC by combination of the grey model and neural networks
Advances in Space Research, 2017Abstract UT1-UTC predictions especially short-term predictions are essential in various fields linked to reference systems such as space navigation and precise orbit determinations of artificial Earth satellites. In this paper, an integrated model combining the grey model GM(1, 1) and neural networks (NN) are proposed for predicting UT1-UTC.
Lei, Yu +7 more
openaire +3 more sources
Advances in Space Research, 2017
Abstract UT1-UTC is an important part of the Earth Orientation Parameters (EOP). The high-precision predictions of UT1-UTC play a key role in practical applications of deep space exploration, spacecraft tracking and satellite navigation and positioning.
Song Jia +3 more
openaire +2 more sources
Abstract UT1-UTC is an important part of the Earth Orientation Parameters (EOP). The high-precision predictions of UT1-UTC play a key role in practical applications of deep space exploration, spacecraft tracking and satellite navigation and positioning.
Song Jia +3 more
openaire +2 more sources
Estimation of the subdiurnal UT1-UTC variations by the least squares collocation method
Astronomical & Astrophysical Transactions, 2000Abstract The result of the two-week VLBI experiment CONT'94 has been processed by the least squares collocation method to calculate the UT1-UTC time series with high temporal resolution (one value every few minutes). It allows us to estimate the influence of tidal variations arising from the world's oceans on the EOP.
O. Titov
openaire +2 more sources
Prediction of UT1-UTC Based on Combination of Weighted Least-Squares and Multivariate Autoregressive
2013High accurate prediction of UT1-UTC is very important for high-precision aircraft navigation and positioning. In this paper, the weighted least-squares (WLS) combined with multivariate autoregressive (MAR) is proposed to predict UT1-UTC with different span.
Zhang-zhen Sun, Tian-he Xu
openaire +2 more sources
2011
The objective of this paper is to extensively discuss the theory behind the multivariate autoregressive prediction technique used elsewhere for forecasting Universal Time (UT1-UTC) and to characterise its performance depending on input geodetic and geophysical data.
Tomasz Niedzielski, Wiesław Kosek
openaire +2 more sources
The objective of this paper is to extensively discuss the theory behind the multivariate autoregressive prediction technique used elsewhere for forecasting Universal Time (UT1-UTC) and to characterise its performance depending on input geodetic and geophysical data.
Tomasz Niedzielski, Wiesław Kosek
openaire +2 more sources
On the geometry of baselines suitable for UT1 estimation with VLBI Intensive sessions
, 2021One hour single baseline VLBI sessions, so-called Intensives, are routinely observed to derive UT1-UTC with a short latency. The selection of baselines for VLBI Intensive sessions and their application for the determination of UT1-UTC is a complex ...
L. Kern +4 more
semanticscholar +1 more source
2023
With the help of Very Long Baseline Interferometry (VLBI), it is possible to determine a large number of parameters, including station and source coordinates as well as the Earth orientation parameters (EOP). Due to the limitation of observations of one hour single baseline sessions, so-called Intensive sessions, only a few parameters such as clock ...
Kern, Lisa Maria +5 more
openaire +1 more source
With the help of Very Long Baseline Interferometry (VLBI), it is possible to determine a large number of parameters, including station and source coordinates as well as the Earth orientation parameters (EOP). Due to the limitation of observations of one hour single baseline sessions, so-called Intensive sessions, only a few parameters such as clock ...
Kern, Lisa Maria +5 more
openaire +1 more source
Journal of Geodesy, 2007
This article presents the application of a multivariate prediction technique for predicting universal time (UT1–UTC), length of day (LOD) and the axial component of atmospheric angular momentum (AAM χ 3). The multivariate predictions of LOD and UT1–UTC are generated by means of the combination of (1) least-squares (LS ...
Tomasz Niedzielski, Wiesław Kosek
openaire +1 more source
This article presents the application of a multivariate prediction technique for predicting universal time (UT1–UTC), length of day (LOD) and the axial component of atmospheric angular momentum (AAM χ 3). The multivariate predictions of LOD and UT1–UTC are generated by means of the combination of (1) least-squares (LS ...
Tomasz Niedzielski, Wiesław Kosek
openaire +1 more source
Comment on ‘A proposal to change the leap-second adjustments to UTC’
MetrologiaIn the paper ‘A proposal to change the leap-second adjustments to UTC’ (Levine 2024 Metrologia 61 055002) the author proposes to replace the present system of leap seconds in UTC by an algorithmic adjustment process based on adjusting UTC at planned ...
G. Petit, G. Tagliaferro
semanticscholar +1 more source
The Future(s) of UT1: A Geophysical Discussion
MetrologiaOnce time became determined by quantum physics (International Atomic Time, TAI), rather than Earth orientation (Universal Time, specifically UT1), the rules for the generally distributed time scale (Coordinated Universal Time, UTC), have linked it to ...
D. C. Agnew
semanticscholar +1 more source