19. Rotation of the Earth (Rotation de la Terre)

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.

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Basic Problems in the Kinematics of the Rotation of the Earth

Symposium - International Astronomical Union ◽

10.1017/s0074180900035907 ◽

1979 ◽

Vol 82 ◽

pp. 7-18 ◽

Cited By ~ 8

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.

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

Symposium - International Astronomical Union ◽

10.1017/s0074180900119539 ◽

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.

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The Origin of Celestial Coordinates

Symposium - International Astronomical Union ◽

10.1017/s0074180900086162 ◽

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.

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COMMISSION 19: ROTATION OF THE EARTH

Proceedings of the International Astronomical Union ◽

10.1017/s1743921308025271 ◽

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/>.

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Commission 19: Rotation of the Earth: (Rotation de la Terre)

Transactions of the International Astronomical Union ◽

10.1017/s0251107x0000256x ◽

2000 ◽

Vol 24 (1) ◽

pp. 32-47

Author(s):

Dennis D. McCarthy ◽

Nicole Capitaine ◽

F. Arias ◽

G. Beutler ◽

P. Brosche ◽

...

Keyword(s):

Earth Rotation ◽

Web Site ◽

Limited Space ◽

The Earth ◽

Rotation Of The Earth ◽

Extensive List

The triennial report of Commission 19 was composed from the contributions of its members. Space does not permit a listing of their names, but their contributions are sincerely appreciated. Unfortunately because of limited space it is also not possible to provide in this report the extensive list of publication of the Commission members. The list of publications is however available on the Commission 19 web site at maia.usno.navy.mil/iauc19.

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Commission 19: Rotation of the Earth (Rotation De La Terre)

Transactions of the International Astronomical Union ◽

10.1017/s0251107x00007124 ◽

1988 ◽

Vol 20 (1) ◽

pp. 179-194

Author(s):

W. J Klepczynski ◽

M. Feissel ◽

B. Kolaczek ◽

F. E Barlier ◽

P. Brosche ◽

...

Keyword(s):

Rotation Rate ◽

Earth Rotation ◽

Earth’S Rotation ◽

International Earth Rotation Service ◽

Earth's Rotation ◽

Core Mantle Boundary ◽

The Core ◽

The Earth ◽

Rotation Of The Earth ◽

Observing Techniques

During the period, there have been several major events which have effected the scope and interest of Commission 19. The most significant of these has been the dissolution of the BIH and IPMS and their replacement by the International Earth Rotation Service (IERS). The correlation of higher frequency fluctuations in the Earth’s rotation rate with changes in the Earth’s Atmospheric Angular Momentum is also significant. Many investigators now seem to believe that the “decade variations„ in the Earth’s rotation rate are caused by torques between the core and mantle caused by the uneven motions at the core-mantle boundary. These events and discoveries have made this an exciting period. It seems that the future holds more in the way of discovery due to the utilization of the more accurate and precise Earth rotation data coming from the modern observing techniques.

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DIVISION A COMMISSION 19: ROTATION OF THE EARTH

Proceedings of the International Astronomical Union ◽

10.1017/s1743921316000636 ◽

2015 ◽

Vol 11 (T29A) ◽

pp. 60-76 ◽

Cited By ~ 1

Author(s):

Chengli Huang ◽

Richard Gross ◽

Florian Seitz ◽

Harald Schuh ◽

Christian Bizouard ◽

...

Keyword(s):

Earth Rotation ◽

Scientific Session ◽

Business Meeting ◽

Research Progress ◽

General Assembly ◽

The Past ◽

The Earth ◽

Short Summary ◽

The Status ◽

Rotation Of The Earth

AbstractThe activities and some research progress of IAU Commission 19 (C19) - Rotation of the Earth - in the past triennial term (2012-2015) is reported in this paper, including the scientific session and business meeting of C19, as well as a business meeting of the IAU/IAG Joint Working Group of “Theory of Earth Rotation” (JWG_ThER) during the XXIX IAU General Assembly in Hawaii, USA. Three reports of JWG_ThER progress, IERS and IAG, eleven reports of national projects and individual institutions, a short summary of the history and heritage of C19, and an Overview of the status and outlook of new Commission A2 are also presented.

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