scholarly journals COMMISSION 19: ROTATION OF THE EARTH

2008 ◽  
Vol 4 (T27A) ◽  
pp. 37-49
Author(s):  
Aleksander Brzezinski ◽  
Chopo Ma ◽  
Véronique Dehant ◽  
Pascale Defraigne ◽  
Jean O. Dickey ◽  
...  
Keyword(s):  
Earth Rotation ◽  
Reference Frames ◽  
International Association ◽  
Vice President ◽  
Past President ◽  
Scientific Investigations ◽  
The Earth ◽  
International Vlbi Service ◽  
Commission President ◽  
Rotation Of The Earth

The Commission supports and coordinates scientific investigations in the Earth rotation and related reference frames. Several changes had been introduced to the structure of Commission 19 since the IAU XXVI General Assembly in Prague, 2006. The Organizing Committee of Commission 19 has been substantially reduced. It consists now of six ex-officio members, the Commission president, vice-president, past president and representatives from the International Association of Geodesy (IAG), International Earth Rotation and Reference Systems Service (IERS), International VLBI Service for Geodesy and Astrometry (IVS), and five members at-large who are nominated by the OC, selected by the Commission members and elected by the IAU GA for a maximum of two terms. The modified terms of reference of Commission 19, the list of members and other details can be found at the Commission website <iau-comm19.cbk.waw.pl/>.

scholarly journals DIVISION I: COMMISSION 19: ROTATION OF THE EARTH

2013 ◽  
Vol 10 (T28B) ◽  
pp. 95-105
Author(s):  
Harald Schuh ◽  
Chengli Huang ◽  
Florian Seitz ◽  
Aleksander Brzezinski ◽  
Christian Bizouard ◽  
...  
Keyword(s):  
International Association ◽  
Scientific Meeting ◽  
Business Meeting ◽  
Division I ◽  
New Members ◽  
The Past ◽  
The Earth ◽  
International Vlbi Service ◽  
Commission President ◽  
Rotation Of The Earth

During the XXVIII IAU General Assembly in Beijing IAU Commission 19 - Rotation of the Earth - held a business meeting and a scientific meeting. The business meeting was held on Wednesday, 29 August 2012 during session 1 (08:30-10:00). It was attended by about 35 participants, and six reports were given. First the activities of IAU Commission 19 during the past triennium (2009–2012) were highlighted by the Commission president. Afterwards, the Commission secretary presented the results of the elections for the next triennium (2012–2015) and a list of new members of the Commission. The designated Commission president provided an outlook into the next triennium, before the representatives of the international bodies and services IAG (International Association of Geodesy), IVS (International VLBI Service for Geodesy and Astrometry), and IERS (International Earth Rotation and Reference Systems Service) gave reports about recent activities. A summary of the business meeting is given below in Section 2. The scientific meeting was held on Thursday, 20 August 2012 during sessions 1 and 2 (08:30-12:30). Eleven presentations were given, and about 40 participants attended the sessions. Summaries of the presentations are provided below in Section 3.

scholarly journals On the eve of the 100th anniversary of IAU Commission 19/A2 “Rotation of the Earth”

2018 ◽  
Vol 13 (S349) ◽  
pp. 325-331
Author(s):  
Zinovy Malkin ◽  
Richard Gross ◽  
Dennis McCarthy ◽  
Aleksander Brzeziński ◽  
Nicole Capitaine ◽  
...  
Keyword(s):  
Earth Rotation ◽  
Reference Frames ◽  
International Association ◽  
General Assembly ◽  
Reference Systems ◽  
Standing Committee ◽  
Earth Orientation ◽  
Terrestrial Reference Frames ◽  
The Earth ◽  
Rotation Of The Earth

AbstractIAU Commission 19 began in 1919 with the birth of the IAU at the Brussels Conference, where Standing Committee 19 on Latitude Variations was established as one of 32 standing committees. At the first IAU General Assembly in 1922, Standing Committee 19 became Commission 19 “Variation of Latitude”. In the beginning, the main topic of the Commission was the investigation of polar motion. Later, its activities included observations and theory of Earth rotation and connections between Earth orientation variations and geophysical phenomena. As a result, in 1964 at the XII IAU General Assembly, the Commission was renamed “Rotation of the Earth”. The investigation of Earth orientation variations is primarily based on observations of natural and artificial celestial objects. Therefore, maintenance of the international terrestrial and celestial reference frames, as well as the coordinate transformation between the frames and the improvement of the model of precession/nutation, have always been among the primary Commission topics. In 1987, the IAU through Commissions 19 and 31 “Time” established, jointly with the International Union of Geodesy and Geophysics, what is now known as the International Earth Rotation and Reference Systems Service. Commission 19 continued to work to develop methods to improve the accuracy and understanding of Earth orientation variations and related reference systems and frames as well as theoretical studies of Earth rotation. In 2015, Commission 19 was renewed as Commission A2 “Rotation of the Earth” continuing Commission 19’s functions and linking the astronomical community to other scientific organizations such as the International Association of Geodesy, International VLBI Service for Geodesy and Astrometry, International GNSS Service, International Laser Ranging Service and International DORIS Service. During its entire history, IAU Commission 19/A2 has always worked in close cooperation with these and other related services to improve the accuracy and consistency of the Earth orientation parameters and celestial and terrestrial reference frames.

The Terrestrial Coordinate System and International Earth-rotation Services

1985 ◽  
Vol 38 (02) ◽  
pp. 216-217
Author(s):  
G. A. Wilkins
Keyword(s):  
Coordinate System ◽  
Earth Rotation ◽  
Reference System ◽  
New Techniques ◽  
Crustal Movements ◽  
Earth Observations ◽  
The Earth ◽  
External Reference ◽  
External Objects ◽  
Rotation Of The Earth

New techniques of measurement make it possible in 1984 to determine positions on the surface of the Earth to a much higher precision than was possible in 1884. If we look beyond the requirements of navigation we can see useful applications of global geodetic positioning to centimetric accuracy for such purposes as the control of mapping and the study of crustal movements. These new techniques depend upon observations of external objects, such as satellites or quasars rather than stars, and they require that the positions of these objects and the orientation of the surface of the Earth are both known with respect to an appropriate external reference system that is ‘fixed’ in space. We need networks of observing stations and analysis centres that monitor the motions of the external objects and the rotation of the Earth. Observations of stars by a transit circle are no longer adequate for this purpose.

The Global Geodetic Observing System (GGOS) – infrastructure underpinning Earth science

2021 ◽  
Author(s):  
Basara Miyahara ◽  
Laura Sánchez ◽  
Martin Sehnal
Keyword(s):  
Mass Transport ◽  
Gravity Field ◽  
Reference Frames ◽  
Earth Science ◽  
International Association ◽  
Analytical Techniques ◽  
Temporal Variations ◽  
Core Element ◽  
The Earth ◽  
Surface Kinematics

&lt;p&gt;The Global Geodetic Observing System (GGOS) is the contribution of Geodesy to the observation and monitoring of the Earth System. Geodesy is the science of determining and representing the shape of the Earth, its gravity field and its rotation as a function of time. A core element to reach this goal are stable and consistent geodetic reference frames, which provide the fundamental layer for the determination of time-dependent coordinates of points or objects, and for describing the motion of the Earth in space. Traditionally, geodetic reference frames have been used for surveying, mapping, and space-based positioning and navigation. With modern instrumentation and analytical techniques, Geodesy is now capable of detecting time variations ranging from large and secular scales to very small and transient deformations with increasing spatial and temporal resolution, high accuracy, and decreasing latency. GGOS has been working closely with components of International Association of Geodesy (IAG) to provide consistent and openly available observations of the spatial and temporal changes of the shape and gravity field of the Earth, as well as the temporal variations of the Earth&amp;#8217;s rotation. These efforts make available a global picture of the surface kinematics of our planet, including the ocean, ice cover, continental water, and land surfaces, as well as estimates of mass anomalies, mass transport, and mass exchange in the System Earth. Surface kinematics and mass transport together are the key to global mass balance determination, and are an important contribution to understanding the energy budget of our planet. In order to play its vital role, GGOS has following missions; a) to provide the observations needed to monitor, map, and understand changes in the Earth&amp;#8217;s shape, rotation, and mass distribution, b) to provide the global geodetic frame of reference that is the fundamental backbone for measuring and consistently interpreting key global change processes and for many other scientific and societal applications, c) to benefit science and society by providing the foundation upon which advances in Earth and planetary system science and applications are built. For the mission, GGOS works tighter with components of the IAG, more specifically, IAG Services, IAG Commissions and IAG Inter-Commission Committees. The IAG Services provide the infrastructure and products on which all contributions of GGOS are based, and the IAG Commissions and IAG Inter-Commission Committees provide expertise and support to address key scientific issues within GGOS. Together with the IAG components, GGOS provides the fundamental infrastructure underpinning Earth sciences and their applications.&lt;/p&gt;

scholarly journals Basic Problems in the Kinematics of the Rotation of the Earth

1979 ◽  
Vol 82 ◽  
pp. 7-18 ◽  
Author(s):  
Bernard Guinot
Keyword(s):  
Earth Rotation ◽  
Rotation Axis ◽  
Earth’S Rotation ◽  
International Astronomical Union ◽  
Earth's Rotation ◽  
The Earth ◽  
International Astronomical ◽  
Rotation Of The Earth

With the advent of more precise methods for measuring Earth rotation, a number of corrections to the apparent directions in space, to the terrestrial references, and to the rotation axis motion have to be carefully applied. It is the duty of the international Astronomical Union to give recommended or conventional expressions of these corrections in order to avoid inextricable difficulties in discussing the evaluated results. However, this task is not sufficient. The concepts used in the description of the Earth's rotation are somewhat obscured by traditions. They should be purified by removing notions which are not directly relevant.

scholarly journals Review of the achievements of project MERIT for the intercomparison of techniques for monitoring the rotation of the Earth

1988 ◽  
Vol 128 ◽  
pp. 227-232
Author(s):  
G. A. Wilkins
Keyword(s):  
Earth Rotation ◽  
Working Group ◽  
New Techniques ◽  
New Methods ◽  
The Earth ◽  
Terrestrial Reference System ◽  
Rotation Of The Earth ◽  
Analyse Data ◽  
Set Up ◽  
International Services

It is generally recognised that the Working Group on the Rotation of the Earth that was set up after IAU Symposium No. 82 has successfully achieved its principal objectives, namely: “to make recommendations on … future international services on earth-rotation” and “to obtain and analyse data on earth-rotation by both current and new methods …”. In particular, by organising Project MERIT, it has stimulated the development and use of new techniques and it has brought together in fruitful collaboration scientists from many countries and disciplines. Other subsidiary objectives have also been achieved and the project has been extended through cooperation with the COTES Working Group on the terrestrial reference system. The possible reasons for this success are also reviewed in the expectation that the conclusions will be relevant to other future projects.

scholarly journals The Origin of Celestial Coordinates

1990 ◽  
Vol 141 ◽  
pp. 51-59
Author(s):  
C. A. Murray
Keyword(s):  
Earth Rotation ◽  
Zero Point ◽  
Rate Of Change ◽  
Reference Systems ◽  
The Earth ◽  
Private Correspondence ◽  
Rotation Of The Earth ◽  
Right Ascension

In 1978, Guinot proposed that, for studies of Earth rotation, the zero point of the apparent “right ascension” coordinate on the true equator should be so chosen that the rate of change of its hour angle is exactly proportional to the inertial rate of rotation of the Earth. It has been subsequently suggested that this concept of the “non-rotating origin” supersede the equinox quite generally as the origin of celestial coordinates. Since this proposal was first put forward, there has been much discussion, and some criticism, from Aoki and his colleagues, both published and in private correspondence. Some of the arguments for and against Guinot's proposal are discussed, as a contribution to the wider debate on reference systems now being carried out under the auspices of the IAU.

The International DORIS Service is preparing the future

2020 ◽  
Author(s):  
Pascale Ferrage ◽  
Laurent Soudarin ◽  
Frank Lemoine
Keyword(s):  
Earth Rotation ◽  
International Association ◽  
Tracking System ◽  
Tectonic Plate ◽  
Plate Motions ◽  
The Earth ◽  
Earth Rotation Parameters ◽  
The Future ◽  
Rotation Parameters

&lt;p&gt;The DORIS system recorded its first measurement on February 3rd, 1990, from the SPOT-2 remote sensing satellite. 30 years after, the system is at its best. DORIS has proven greatly valuable for geodesy and geophysics applications: measuring tectonic plate motions, determination of the rotation and the gravity parameters of the Earth, contributing to the international reference system. Technological and methodological improvements have allowed the improvement in the estimates of the positions of the DORIS tracking ground stations, the Earth rotation parameters and other geodetic variables such as the geocenter and the scale of the ITRF.&lt;br&gt;The International DORIS Service (IDS) was created in 2003 under the umbrella of the International Association of Geodesy (IAG) to foster scientific research related to the French DORIS tracking system and to deliver scientific products, mostly related to the International Earth rotation and Reference systems Service (IERS). Since its start, the organization has continuously evolved, leading to additional and improved operational products from an expanded set of DORIS Analysis Centers. IDS is now based on a reinforced structure with two Data Centers, six Analysis Centers, four Associate Analysis Centers, and a Combination Center. Using the experience gained in the preparation of the ITRFs, many improvements were made all along both in data analysis and on technical aspects. After the IDS Retreat held in June 2018, the IDS GB worked on the development of a strategic plan for the IDS. In the coming years, IDS will focus on growing the community, extending the DORIS applications, and improving the technology, the infrastructure and the processing.&lt;br&gt;This presentation addresses the recent achievements made by IDS and how the service is preparing the future.&lt;/p&gt;

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