scholarly journals The Background to the Merit/Cotes Recommendations on the Terrestrial and Celestial Reference Systems

1986 ◽  
Vol 7 ◽  
pp. 81-84
Author(s):  
G A Wilkins
Keyword(s):  
International Collaboration ◽  
Earth Rotation ◽  
Reference Frames ◽  
Radio Sources ◽  
Reference Systems ◽  
International Earth Rotation Service ◽  
Earth Rotation Parameters ◽  
Working Groups ◽  
Rotation Parameters ◽  
Better Than

AbstractThe MERIT programme of international collaboration to monitor earth-rotation and to intercompare the techniques of observation and analysis has fostered the development of the use of space techniques. Earth-rotation parameters are now determined regularly with a precision that is better than 1 milliarcsecond () and the relative positions of the observing stations are determined to better than 1 decimetre (0.1 m). It is therefore necessary that the terrestrial and celestial reference frames be defined more precisely. The MERIT and COTES Working Groups have proposed that new conventional terrestrial and celestial reference systems be established and that the maintenance of these systems be the responsibility of a new International Earth Rotation Service. The new reference frames are to be based on the adoption of positions and motions of designated stations and extragalactic radio sources. Appropriate models and parameters will be associated with these frames to form reference systems so that observations can be used to determine the rotation of the terrestrial frame with respect to the celestial frame.

scholarly journals SLR Contribution to Investigation of Polar Motion

2000 ◽  
Vol 178 ◽  
pp. 267-276
Author(s):  
Zinovy Malkin
Keyword(s):  
Earth Rotation ◽  
Polar Motion ◽  
Satellite Laser Ranging ◽  
Laser Ranging ◽  
International Earth Rotation Service ◽  
Global Tracking ◽  
International Earth Rotation ◽  
Earth Rotation Parameters ◽  
Rotation Parameters

AbstractThe Satellite Laser Ranging (SLR) technique has been used to determine Earth Rotation Parameters (ERP) for over twenty years. Most of results contributed to the International Earth Rotation Service (IERS) are based on analysis of observations of Lageos 1 & 2 satellites collected by the global tracking network of about 40 stations. Now five analysis centers submit operational (with 2–15 days delay) solutions and about ten analysis centers contribute yearly final (up to 23 years) ERP series. Some statistics related to SLR observations and analysis are presented and analyzed. Possible problems in SLR observations and analysis and ways of its solution are discussed.

scholarly journals The Effects of the Reference Frames and of their Realization on the Earth Rotation Parameters Computed from Different Observational Techniques

1980 ◽  
Vol 56 ◽  
pp. 135-144
Author(s):  
Nicole Capitaine ◽  
Martine Feissel
Keyword(s):  
Reference Frame ◽  
Earth Rotation ◽  
High Frequency ◽  
Reference Frames ◽  
The Earth ◽  
Earth Rotation Parameters ◽  
Rotation Parameters ◽  
Using Data ◽  
Observational Techniques ◽  
Numerical Estimations

AbstractThe inaccuracies in the reference frames actually realized by the different techniques for measuring the Earth’s rotation are theoretically investigated. The intercomparison of the available series of measurements provides numerical estimations of these defects. Using data corrected for reference frame effects high frequency fluctuations of UT1 are detected.

scholarly journals Astrometric Latitude and Time Observational Database at Shanghai Observatory

1993 ◽  
Vol 156 ◽  
pp. 433-433
Author(s):  
Zheng-Xin Li ◽  
You-Fen Chen ◽  
Chang-Xia Qian
Keyword(s):  
Observational Data ◽  
Earth Rotation ◽  
International Earth Rotation Service ◽  
The Past ◽  
International Earth Rotation ◽  
Earth Rotation Parameters ◽  
The World ◽  
Time Determination ◽  
Rotation Parameters ◽  
The Moment

After the closing of Bureau International de L'Heure (BIH) and the establishment of International Earth Rotation Service (IERS) at the end of 1987. Shanghai Observatory has been the institute where the astrometric latitude and time observational data are collected and treated. During the past four years, about 75,293 measurements in latitude or time determination have been obtained by the 64 optical astrometric instruments over the world from which the five-day Earth Rotation Parameters of the 1988–1990 period have still been reduced. Twelve Quarterly Report on the optical ERP have been distributed. Since the beginning of 1991 the regular reduction of the ERP has been stopped but the collecting of the observational data is still going on in Shanghai Observatory in order to meet the requirements of the scientists who are still interested on the studies concerned with these observations. There are still 42 optical astrometric instruments taking part into the regular observations at the moment.

scholarly journals The NAVOBSY/NRL Program for the Determination of Earth Rotation and Polar Motion

1979 ◽  
Vol 82 ◽  
pp. 211-215
Author(s):  
K. J. Johnston ◽  
J. H. Spencer ◽  
C. H. Mayer ◽  
W. J. Klepczynski ◽  
G. Kaplan ◽  
...  
Keyword(s):  
Earth Rotation ◽  
Polar Motion ◽  
The United States ◽  
Precise Determination ◽  
Naval Research ◽  
Radio Sources ◽  
Naval Observatory ◽  
Earth Rotation Parameters ◽  
Rotation Parameters

The joint program of NAVOBSY/NRL is discussed.The United States Naval Observatory (NAVOBSY) and the Naval Research Laboratory (NRL) are collaborating in a program to apply radio interferometric techniques to the determination of variations in Earth rotation, polar motion, and improved astronomical position reference systems. Investigations of VLBI and connected interferometer techniques and radio sources for astrometic application have been in progress for several years as part of the NRL radio astronomy program, and currently NRL and NAVOBSY are carrying out experimental programs to investigate VLBI time transfer techniques and UT determination using the connected element interferometer of the NRAO in Green Bank. Some previous results of observations using the Green Bank interferometer and proposed plans for operation as a dedicated system over a period of time to evaluate effectiveness for precise determination of Earth rotation parameters are discussed.

scholarly journals Requirements for Earth Rotation Parameters

1986 ◽  
Vol 7 ◽  
pp. 63-64
Author(s):  
Dennis D. McCarthy
Keyword(s):  
Polar Motion ◽  
Reference Frames ◽  
Universal Time ◽  
Reference Systems ◽  
Sidereal Time ◽  
Earth Orientation Parameters ◽  
Earth Rotation Parameters ◽  
Definition Of ◽  
Orientation Parameters ◽  
Better Than

AbstractObservations of Earth orientation parameters (polar motion and Universal Time) have reached a level of accuracy which challenges the definition of the reference systems which these observations seek to relate. Observational accuracies of better than in polar motion and in Universal Time are now routinely available. Urgent requirements therefore exist now for the IAU to take a fresh look at the concepts and definitions of the reference systems as well as reference frames. Of particular concern are the definitons of the equinox, the terrestrial reference pole, the zero of longitude and sidereal time.

scholarly journals Remarks concerning reference frames

1988 ◽  
Vol 128 ◽  
pp. 21-23
Author(s):  
James A. Hughes
Keyword(s):  
Earth Rotation ◽  
Reference Frames ◽  
Empirical Relationship ◽  
Washington Dc ◽  
The Moon ◽  
Earth Rotation Parameters ◽  
Used Car ◽  
Rotation Parameters ◽  
Orientation Parameters

Twenty years ago I published A Catalog of 939 PZT Stars on the System of the FK4. At the time it was well received and indeed it did tighten up various PZT results. As I recall, the catalog, among other things, confirmed an empirical relationship between the Richmond, Florida and Washington, DC instruments which had been derived by Prof. Markowitz. In any event, I planned to follow up on this work, but an assignment to El Leoncito, Argentina intervened. Perhaps it was just as well because other things were happening. Astronauts were soon tramping about the moon and littering up the place with a used car and something called a retro-reflector. Radio astronomers were constantly refining the astrometric potential of their interferometric techniques; strange, high-z, starlike objects had been detected a few years earlier; shiny, new satellites were launched; and shortly the science of determining Earth Rotation Parameters (ERP), or “Orientation Parameters” if you prefer, was to explode with vitality and to reach precisions and accuracies never before achieved. As a matter of fact, the new riches became so numerous that, like the proverbial kid in the candy store, the ERP community was, to some extent, forced to choose among some of them. Thus was born the MERIT campaign.

scholarly journals The effect of earthquakes on the ERP during 1977–1985

1988 ◽  
Vol 128 ◽  
pp. 399-404 ◽  
Author(s):  
Richard S. Gross
Keyword(s):  
Earth Rotation ◽  
The Earth ◽  
Time Period ◽  
Earth Rotation Parameters ◽  
Rotation Parameters ◽  
Large Earthquakes

The effect on the Earth Rotation Parameters (ERP) of all the large earthquakes that occurred during 1977–1985 is evaluated. It is found that they cannot have caused the variations observed in the ERP during this time period.

scholarly journals High Frequency Variations of Earth Rotation Parameters from GPS and GLONASS Observations

Sensors ◽  
2015 ◽  
Vol 15 (2) ◽  
pp. 2944-2963 ◽  
Author(s):  
Erhu Wei ◽  
Shuanggen Jin ◽  
Lihua Wan ◽  
Wenjie Liu ◽  
Yali Yang ◽  
...  
Keyword(s):  
Earth Rotation ◽  
High Frequency ◽  
Earth Rotation Parameters ◽  
Rotation Parameters ◽  
Frequency Variations
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