Earth Orientation Parameter Analysis from VLBI Data

1998 ◽  
pp. 318-324
Author(s):  
V. Thorandt ◽  
A. Reinhold ◽  
D. Ullrich ◽  
J. Ihde ◽  
J. Campbell ◽  
...  
Keyword(s):  
Parameter Analysis ◽  
Orientation Parameter ◽  
Earth Orientation Parameter ◽  
Earth Orientation ◽  
Vlbi Data

Status of ESA’s independent Earth Orientation Parameter products

2020 ◽  
Author(s):  
Erik Schoenemann ◽  
Tim Springer ◽  
Michiel Otten ◽  
Volker Mayer ◽  
Sara Bruni ◽  
...  
Keyword(s):  
Earth Rotation ◽  
Orientation Parameter ◽  
Earth Orientation Parameter ◽  
International Earth Rotation Service ◽  
International Gnss Service ◽  
Earth Orientation Parameters ◽  
Earth Orientation ◽  
The Earth ◽  
International Earth Rotation ◽  
Orientation Parameters

<p>The availability of highly accurate, up-to-date Earth Orientation Parameters is of major importance for all positioning and navigation applications on Earth, Sea, Air and also in Space. This is equally true for ESA missions and the EU space programs, e.g. Galileo, EGNOS and Copernicus.</p><p>In the frame of its responsibility to provide the Geodetic reference for ESA missions, ESA’s Navigation Support Office at ESOC is already contributing to the realisation of the International Terrestrial Reference Frame (ITRF) and the combined Earth Orientation Parameters provided by the International Earth Rotation Service (IERS). The contribution is realised through individual contributions to international services such as the International GNSS Service (IGS), the International Laser Ranging Services (ILRS), the International DORIS Service (IDS), the International Earth Rotation Service (IERS) and in the future also to the International VLBI Service (IVS).</p><p>For the combination and the long-term predictions of the Earth orientation products ESA is still relying on the International Earth Rotation Service (IERS). Over the past years, ESA repeatedly experienced problems with outdated or missing predictions of the Earth orientation parameters (Bulletin A). Considering the importance of up-to-date Earth orientation parameters, the dependence on a single source outside Europe is considered a risk for European industry, for ESA missions and for EU programmes. For this reason, ESA initiated in 2017 a study with the target to develop independent ESA Earth Orientation parameter products. This study, executed by a consortium led by the Deutsches Geodätisches Forschungsinstitut (DGFI-TUM), is expected to finish in the course of this year.</p><p>In this presentation we will give an overview of ESAs up-to-date reference products and discuss their quality. It will outline the combination approach and discuss the way forward to an fully operational provision of the ESA Earth Orientation Parameter products.</p>

scholarly journals Determination of EOP from VLBI in IAA

2000 ◽  
Vol 178 ◽  
pp. 261-265
Author(s):  
E. Skurihkina
Keyword(s):  
Orientation Parameter ◽  
Earth Orientation Parameter ◽  
Earth Orientation ◽  
Relativistic Models

AbstractResults of Earth orientation parameter (EOP) determinations from NEOS-A and CORE programs reduced using the package OCCAM version 3.5 at the Institute of Applied Astronomy of Russian Academy of Science (IAA) are presented. Results of EOP determination using different reference stations, relativistic models, the IERS Standards (1992) and IERS Conventions (1996) are also presented.

scholarly journals Future of Earth Orientation Predictions

2010 ◽  
Vol 45 (2) ◽  
pp. 107-110 ◽  
Author(s):  
B. Luzum
Keyword(s):  
Orientation Parameter ◽  
Earth Orientation Parameter ◽  
Earth Orientation ◽  
User Community ◽  
The Earth

Future of Earth Orientation Predictions Earth orientation prediction has undergone a number of changes over the last few decades in response to changing conditions in the Earth orientation parameter user community. However, considering the recent pace of change, it is likely that the rate at which innovations are introduced into the prediction process will increase. Potential drivers for change are discussed and possible directions for change are outlined.

scholarly journals The Long Term Stability of VLBI Earth Orientation Measurements

1988 ◽  
Vol 129 ◽  
pp. 369-370
Author(s):  
T. M. Eubanks ◽  
J. A. Steppe
Keyword(s):  
Laser Ranging ◽  
Lunar Laser Ranging ◽  
Earth Orientation ◽  
Long Term Stability ◽  
Long Baseline ◽  
Lunar Laser ◽  
Tectonic Motion ◽  
Vlbi Data ◽  
Different Sources

Tectonic motions will, in general, change the orientation as well as the length of baselines used in Very Long Baseline Interferometry (VLBI), and will thus cause slow divergences between Earth orientation results obtained with different VLBI networks, as well as between VLBI results and those obtained by Satellite Laser Ranging (SLR) and Lunar Laser Ranging (LLR). Such drifts (on the order of a milliarcsecond /year) are inherently interesting as well as being significant in combinations of orientation results from different sources. The geodetic study of tectonic motions is also closely connected to research into the nature and causes of systematic errors in data from the modern techniques of space geodesy. We describe both a special coordinate system found to be of use in the analysis of VLBI data and tectonic motion estimates for a VLBI baseline stretching from California to Australia.

Combination of GNSS and VLBI data for consistent estimation of Earth Orientation Parameters

2020 ◽  
Author(s):  
Lisa Lengert ◽  
Hendrik Hellmers ◽  
Claudia Flohrer ◽  
Daniela Thaller ◽  
Alexander Kehm
Keyword(s):  
Normal Equation ◽  
Earth Orientation Parameters ◽  
Earth Orientation ◽  
Starting Point ◽  
Station Coordinates ◽  
Space Geodetic Techniques ◽  
Vlbi Data ◽  
Gnss Data ◽  
The Impact ◽  
Orientation Parameters

<p>We present the current activities of the Federal Agency for Cartography and Geodesy (BKG) towards a combined processing of VLBI and GNSS data.  The main goal of the combined analyses of the two different space-geodetic techniques is the improvement of the consistency between the techniques through common parameters, as Earth Orientation Parameters (EOPs), but also station coordinates and tropospheric parameters through local ties and atmospheric ties, respectively.</p><p>The combination of GNSS data with VLBI 24-hour sessions and VLBI Intensive sessions is studied in detail w.r.t. EOPs to exploit he combination benefit to its maximum extend. We analyse the impact of the combination on the technique-specific parameters (e.g. dUT1), but also on common parameters (e.g. LOD, polar motion, station coordinates). When using GNSS data in combination with VLBI Intensive sessions, we can demonstrate an accuracy improvement of the dUT1 time series.</p><p>We also study the combination of troposphere parameters, focusing first on the validation of the technique-specific troposphere parameters at VLBI-GNSS co-located sites and on the modelling of the corresponding atmospheric ties.</p><p>BKGs primary interest is the combination of GNSS and VLBI data on the observation level. However, the current combination efforts are based on the normal equation level using technique-specific SINEX files as a starting point.</p>

scholarly journals Determination of the Long Period Nutation Terms from Optical Astrometry and VLBI Data

2000 ◽  
Vol 178 ◽  
pp. 607-612
Author(s):  
P. Yaya ◽  
C. Bizouard ◽  
C. Ron
Keyword(s):  
Linear Trend ◽  
Earth Orientation Parameters ◽  
Earth Orientation ◽  
Long Period ◽  
The Earth ◽  
Vlbi Data ◽  
Orientation Parameters

AbstractA 100-year long optical astrometric series of the Earth Orientation Parameters produced by a Czech team (Vondrák et al., 1998) has been analysed in order to determine components of nutation. Our interest is mostly focused on the long periodic terms: 18.6-year term, 9.3-year term and linear trend, still correlated in VLBI series which cover only the last 20 years. A comparison has been made with the corresponding values determined from the VLBI series.

scholarly journals Baseline-dependent clock offsets in VLBI data analysis

2021 ◽  
Vol 95 (12) ◽  
Author(s):  
Hana Krásná ◽  
Frédéric Jaron ◽  
Jakob Gruber ◽  
Johannes Böhm ◽  
Axel Nothnagel
Keyword(s):  
Data Analysis ◽  
Reference Frames ◽  
Earth Orientation Parameters ◽  
Earth Orientation ◽  
Long Baseline ◽  
Station Coordinates ◽  
Vlbi Data ◽  
Group Delays ◽  
The Impact ◽  
Orientation Parameters

AbstractThe primary goal of the geodetic Very Long Baseline Interferometry (VLBI) technique is to provide highly accurate terrestrial and celestial reference frames as well as Earth orientation parameters. In compliance with the concept of VLBI, additional parameters reflecting relative offsets and variations of the atomic clocks of the radio telescopes have to be estimated. In addition, reality shows that in many cases significant offsets appear in the observed group delays for individual baselines which have to be compensated for by estimating so-called baseline-dependent clock offsets (BCOs). For the first time, we systematically investigate the impact of BCOs to stress their importance for all kinds of VLBI data analyses. For our investigations, we concentrate on analyzing data from both legacy networks of the CONT17 campaign. Various aspects of BCOs including their impact on the estimates of geodetically important parameters, such as station coordinates and Earth orientation parameters, are investigated. In addition, some of the theory behind the BCO determination, e.g., the impact of changing the reference clock in the observing network on the BCO estimate is introduced together with the relationship between BCOs and triangle delay closures. In conclusion, missing channels, and here in particular at S band, affecting the ionospheric delay calibration, are identified to be the dominant cause for the occurrence of significant BCOs in VLBI data analysis.

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