2.2. Working Group 2: Conceptual Definitions of Reference Coordinate Systems for Earth Dynamics

1975 ◽  
Vol 26 ◽  
pp. 21-26
Keyword(s):  
Coordinate System ◽  
Working Group ◽  
General Character ◽  
Coordinate Systems ◽  
Reference Coordinate System ◽  
Group 2 ◽  
Definition Of ◽  
Earth Dynamics

An ideal definition of a reference coordinate system should meet the following general requirements:1. It should be as conceptually simple as possible, so its philosophy is well understood by the users.2. It should imply as few physical assumptions as possible. Wherever they are necessary, such assumptions should be of a very general character and, in particular, they should not be dependent upon astronomical and geophysical detailed theories.3. It should suggest a materialization that is dynamically stable and is accessible to observations with the required accuracy.

scholarly journals Reference Coordinate System Requirements for Space Physics and Astronomy

1980 ◽  
Vol 56 ◽  
pp. 71-75
Author(s):  
J. D. Mulholland
Keyword(s):  
Boundary Conditions ◽  
Coordinate System ◽  
Space Physics ◽  
Coordinate Frame ◽  
Coordinate Systems ◽  
Reference Coordinate System ◽  
System Requirements ◽  
Internal Coherence ◽  
Earth Dynamics

AbstractChanges in reference coordinate systems have major implications well beyond the realm of Earth dynamics. Definitions that serve geodynamic convenience may cause considerable effects for other disciplines. After presenting some typical areas in which coordinate frame definitions are important, recommendations are given for criteria to be considered as boundary conditions in discussing changes. These cover such qualities as observability, complexity, stability, internal coherence and uniqueness.

2.3. Working Group 3: Practical Realization of the Reference Coordinate Systems

1975 ◽  
Vol 26 ◽  
pp. 27-38
Keyword(s):  
Coordinate System ◽  
Working Group ◽  
Fundamental Constants ◽  
Practical Realization ◽  
Coordinate Systems ◽  
Reference Coordinate System ◽  
Measuring Techniques ◽  
Group 3 ◽  
Computational Procedures ◽  
Better Than

For a reference coordinate system to be useful to Blarth dynamics it must clearly display the phenomena of interest in a systematic and unambiguous way, free of detailed assumptions. For a clear display, it is absolutely essential that the system be realized to an accuracy substantially better than has been obtained heretofore. This demands not only improved measuring techniques and instruments, but also precise specification of computational procedures, assumptions, fundamental constants, etc., and meticulous implementation.

2.1. Working Group 1: Requirements for Coordinate Systems for Earth Dynamics

1975 ◽  
Vol 26 ◽  
pp. 15-20
Keyword(s):  
Coordinate System ◽  
Working Group ◽  
Global Scale ◽  
Coordinate Systems ◽  
Tectonic Plates ◽  
The Earth ◽  
International Projects ◽  
The Subject ◽  
Earth Dynamics ◽  
Group 1

As initial guidance for its deliberations, Working Group 1 accepted the objective implied in the Colloquium title and the more explicit description contained in the First Circular announcing the Colloquium:Earth dynamics is currently the subject of intensive world-wide research efforts. As a consequence of the new insights into Earth dynamics and acceptance of the hypothesis of moving tectonic plates, as well as the ability to measure crustal motions on a global scale with a precision of a few centimeters, a number of national and international projects have been organized to pursue these investigations. In all these efforts, a common feature is the necessity for a very well defined coordinate system to which all observations can be referred and in which theories can be formulated. At this time there is no widely accepted coordinate system in the Earth or in space which is defined with the precision needed for ongoing geodynamics research.

scholarly journals The Celestial Reference System in Relativistic Framework

1990 ◽  
Vol 141 ◽  
pp. 99-110
Author(s):  
Han Chun-Hao ◽  
Huang Tian-Yi ◽  
Xu Bang-Xin
Keyword(s):  
Coordinate System ◽  
Reference Frame ◽  
Reference System ◽  
Light Deflection ◽  
Coordinate Systems ◽  
Definition Of ◽  
Celestial Sphere ◽  
Celestial Reference System ◽  
Relativistic Framework

The concept of reference system, reference frame, coordinate system and celestial sphere in a relativistic framework are given. The problems on the choice of celestial coordinate systems and the definition of the light deflection are discussed. Our suggestions are listed in Sec. 5.

Applications of the Global Coordinate System

2011 ◽  
Author(s):  
Yves Balasko
Keyword(s):  
Coordinate System ◽  
Critical Points ◽  
Global Coordinate System ◽  
Coordinate Systems ◽  
Analytical Characterization ◽  
Equilibrium Manifold ◽  
System P ◽  
Definition Of

The global coordinate system for the equilibrium manifold follows from: (1) the determination of the unique fiber F(b) through the equilibrium (ρ‎, ω‎) where b = φ‎((ρ‎, ω‎) = (ρ‎, ρ‎ · ρ‎1, …, ρ‎ · ρ‎m); and (2) the determination of the location of the equilibrium (ρ‎, ω‎) within the fiber F(b) viewed as a linear space of dimension (ℓ − 1)(m − 1) and, therefore, parameterized by (ℓ − 1)(m − 1) coordinates. If there is little leeway in determining the fiber F(b) through the equilibrium (ρ‎, ω‎), there are different ways of representing the equilibrium (ρ‎, ω‎) within its fiber F(b). This leads to the definition of coordinate systems (A) and (B) for the equilibrium manifold. This chapter defines these two coordinate systems and applies them to obtain an analytical characterization of the critical equilibria, i.e., the critical points of the natural projection.

scholarly journals Reference Coordinate Systems for Earth Dynamics: A Preview

1980 ◽  
Vol 56 ◽  
pp. 1-22 ◽  
Author(s):  
Ivan I. Mueller
Keyword(s):  
Coordinate System ◽  
Coordinate Systems ◽  
Inertial Coordinate System ◽  
Terrestrial System ◽  
The Earth ◽  
Earth Dynamics

AbstractA common requirement for all geodynamic investigations is a well-defined coordinate system attached to the earth in some prescribed way, as well as a well-defined inertial coordinate system in which the motions of the terrestrial system can be monitored. This paper deals with the problems encountered when establishing such coordinate systems and the transformations between them. In addition, problems related to the modeling of the deformable earth are discussed.

scholarly journals Indexing of icosahedral quasiperiodic crystals

1986 ◽  
Vol 1 (1) ◽  
pp. 13-26 ◽  
Author(s):  
John W. Cahn ◽  
Dan Shechtman ◽  
Denis Gratias
Keyword(s):  
Fourier Transform ◽  
Electron Diffraction ◽  
Single Crystal ◽  
Coordinate System ◽  
Powder Diffraction ◽  
Simple Application ◽  
Coordinate Systems ◽  
Diffraction Patterns ◽  
Definition Of ◽  
Crystal Electron

Since the definition of quasiperiodicity is intimately connected to the indexing of a Fourier transform, for the case of an icosahedral solid, the step necessary to prove, using diffraction, that an object is quasiperiodic, is described. Various coordinate systems are discussed and reasons are given for choosing one aligned with a set of three orthogonal two-fold axes. Based on this coordinate system, the main crystallographic projections are presented and several analyzed single-crystal electron diffraction patterns are demonstrated. The extinction rules for three of the five icosahedral Bravais quasilattices are compared, and some simple relationships with the six-dimensional cut and projection crystallography are derived. This analysis leads to a simple application for indexing powder diffraction patterns.

scholarly journals Concept of spatial coordinate systems, their defining and implementation as a precondition in geospatial applications

2015 ◽  
Vol 95 (4) ◽  
pp. 77-102
Author(s):  
Zoran Nedeljkovic ◽  
Aleksandar Sekulic
Keyword(s):  
Geographic Information Systems ◽  
Coordinate System ◽  
Spatial Data ◽  
Spatial Databases ◽  
Spatial Information ◽  
Reference Network ◽  
Abstract Entity ◽  
Coordinate Systems ◽  
Definition Of ◽  
Geodetic Reference Frame

There are many users of spatial information, and quite large interest about the nature and genesis of such information. Different users found spatial information in the form of maps, plans or alphanumerical tables. Recently, there are more often in the form of spatial databases, and in the form of geographic information systems. What is behind these spatial data? On what foundation are they designed? In this article we look at the basic aspects of space, dimensionality and global coordinate systems in applications of global geospatial research. Here is explained the definition of the coordinate system as an abstract entity and, consequently, its implementation or establishment in the form of a geodetic reference frame, as real geodetic reference network. The applicative aspect of coordinate systems in this article is emphasized through recommendations and considerations during usage of their different implementations.

scholarly journals COORDINATION OF PLANETARY COORDINATE SYSTEM RECOMMENDATIONS BY THE IAU WORKING GROUP ON CARTOGRAPHIC COORDINATES AND ROTATIONAL ELEMENTS – 2020 STATUS AND FUTURE

2020 ◽  
Vol XLIII-B3-2020 ◽  
pp. 1091-1097
Author(s):  
B. A. Archinal ◽  
C. H. Acton ◽  
A. Conrad ◽  
T. C. Duxbury ◽  
D. Hestroffer ◽  
...  
Keyword(s):  
Coordinate System ◽  
Working Group ◽  
Coordinate Systems ◽  
International Astronomical Union ◽  
International Astronomical ◽  
Cartographic Coordinates ◽  
Published Report ◽  
Near Term ◽  
Future Work ◽  
Community Input

Abstract. Our goal is to request input from the lunar and planetary community regarding issues of planetary coordinate systems and cartography standards. We begin with an overview of the work of the International Astronomical Union Working Group on Cartographic Coordinates and Rotational Elements. We briefly describe the operations and membership of the Working Group, some of the various uses of the recommendations it makes, our most recent (2018) published report and the recommendations therein, and the outlook for our next such report. We then consider several issues and questions regarding the future of the Working Group and regarding planetary cartography and planetary data spatial infrastructure in general. This includes possible near-term projects, how we and others might collect and consider community input and includes some ideas regarding possible outcomes or future work that will need to be addressed by the Working Group or other organizations.

scholarly journals On the Absolute Orientation of the Selenodetic Reference Frame

1981 ◽  
Vol 63 ◽  
pp. 281-286
Author(s):  
V. S. Kislyuk
Keyword(s):  
Coordinate System ◽  
Center Of Mass ◽  
The Moon ◽  
Coordinate Systems ◽  
Inertial Coordinate System ◽  
Reference Coordinate System ◽  
The Earth ◽  
Principal Axes ◽  
The Mean ◽  
Selection Of

The selection of selenodetic reference coordinate system is an important problem in astronomy and selenodesy. For the purposes of reduction of observations, planning and executing space missions to the Moon, it is necessary, in any case, to know the orientation of the adopted selenodetic reference system in respect to the inertial coordinate system.Let us introduce the following coordinate systems: C(ξc, ηc, ζc), the Cassini system which is defined by the Cassini laws of the Moon rotation;D(ξd, ηd, ζd), the dynamical coordinate system, whose axes coincide with the principal axes of inertia of the Moon;Q(ξq, ηq, ζq), the quasi-dynamical coordinate system connected with the mean direction to the Earth, which is shifted by 254" West and 75" North from the longest axis of the dynamical system (Williams et al., 1973);S(ξs, ηs, ζs), the selenodetic coordinate system, which is practically realized by the positions of the points on the Moon surface given in Catalogues;I(X,Y,Z), the space-fixed (inertial) coordinate system. All the systems are selenocentric with the exception of S(ξs, ηs, ζs On the whole, the origin of this system does not coincide with the center of mass of the Moon.

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