Mapping the Spacetime Metric with a Global Navigation Satellite System–extension of study: Recovering of orbital constants using inter-satellites links (original) (raw)
Related papers
Definition and realization of the celestial intermediate reference system
Proceedings of the International Astronomical Union, 2007
The transformation between the International Terrestrial Reference System (ITRS) and the Geocentric Celestial Reference system (GCRS) is an essential part of the models to be used when dealing with Earth's rotation or when computing directions of celestial objects in various systems. The 2000 and 2006 IAU resolutions on reference systems have modified the way the Earth orientation is expressed and adopted high accuracy models for expressing the relevant quantities for the transformation from terrestrial to celestial systems. First, the IAU 2000 Resolutions have refined the definition of the astronomical reference systems and transformations between them and adopted the IAU 2000 precession-nutation. Then, the IAU 2006 Resolutions have adopted a new precession model that is consistent with dynamical theories and have addressed definition, terminology or orientation issues relative to reference systems and time scales that needed to be specified after the adoption of the IAU 2000 r...
Highlights of Astronomy, 2005
The IAU Joint Discussion 16 (JD16) was held in conjunction with the XXVth General Assembly in July, 2003. Papers related to the maintenance of the International Celestial Reference System were presented in the one-day session, and these were followed by discussion that pointed out the need for standard nomenclature. This issue was addressed by the formation of a Division 1 Working Group on the subject. JD16 also pointed out the requirement for a dynamical expression for precession which was addressed by the creation of a Division 1 Working Group on Precession and the Ecliptic. It also showed that although plans are being implemented to provide reference frames for the future, there is a need for improved coordination of astrometric observations. Finally it should be noted that the discussion pointed out the concern for the future organization of IAU Division 1.
The Next Generation Celestial Reference Frame
arXiv: Instrumentation and Methods for Astrophysics, 2019
Astrometry, the measurement of positions and motions of the stars, is one of the oldest disciplines in Astronomy, extending back at least as far as Hipparchus' discovery of the precession of Earth's axes in 190 BCE by comparing his catalog with those of his predecessors. Astrometry is fundamental to Astronomy, and critical to many aspects of Astrophysics and Geodesy. In order to understand our planet's and solar system's context within their surroundings, we must be able to to define, quantify, study, refine, and maintain an inertial frame of reference relative to which all positions and motions can be unambiguously and self-consistently described. It is only by using this inertial reference frame that we are able to disentangle our observations of the motions of celestial objects from our own complex path around our star, and its path through the galaxy, and the local group. Every aspect of each area outlined in the call for scientific frontiers in astronomy in the ...
Major concepts of recent celestial and terrestrial reference systems
Annual of Navigation, 2004
The XXIV IAU General Assembly in Manchester in 2000, recommended to replace on 1 January 2003, the existing celestial reference systems with the International Celestial Reference System (ICRS). The International Terrestrial Reference System (ITRS) has formally been implemented in 1991, on the basis of the Resolution 2 of the XX IUGG General Assembly in Vienna in 1991. The ICRS consists of the ensemble of the Barycentric Celestial Reference System (BCRS) and the Geocentric Celestial Reference System (GCRS) with coordinate times Barycentric Coordinate Time (TCB) and Geocentric Coordinate Time (TCG), respectively. New celestial reference systems are built up on the basis of the relativistic theory of astronomical reference systems. Also new definition of the Intermediate Reference System (IRS) that links the celestial systems with the terrestrial system has been introduced. Orientation of the celestial IRS and the terrestrial IRS using CIP, CEO and TEO is discussed. Motion of the IRS w...
Journal of Computational Methods in Sciences and Engineering, 2004
The recent introduction of new star catalogues referred to the new ICRF reference frame gives special interest to the study of the orientation errors of this freferences frame with respect to the dynamical reference frame defined by means of planetary theory. Several methods can be used for this purpose. One of them is based in an optimal control method where the residuals given from the differences between the calculated and observated positions for a set of minor planets on a long time-span, and we use the residual function as cost function. This method requires a previous correction of the elements of the asteroids in order to consider the most precise calculated positions. For this purpose a set of observated positions asteroids in the time span 1836-1996 are taken. From this initial correction we compare the calculated and observated positions from a differential rotation with a linear correction in time around each axis an a model of correction is got.
Introducing relativity in global navigation satellite systems
Annalen der Physik, 2007
Today, the Global Navigation Satellite Systems, used as global positioning systems, are the GPS and the GLONASS. They are based on a Newtonian model and hence they are only operative when several relativistic effects are taken into account. The most important relativistic effects (to order 1/c 2 ) are: the Einstein gravitational blue shift effect of the satellite clock frequency (Equivalence Principle of General Relativity) and the Doppler red shift of second order, due to the motion of the satellite (Special Relativity). On the other hand, in a few years the Galileo system will be built, copying the GPS system unless an alternative project is designed. In this work, it will be also shown that the SYPOR project, using fully relativistic concepts, is an alternative to a mere copy of the GPS system. According to this project, the Galileo system would be exact and there would be no need for relativistic corrections.
A Search for Invariant Relative Satellite Motion
4th Workshop on …, 2005
Relative motion between two or more satellites in formation has been studied for quite a long time, as the works of WH Clohessy and RS Wiltshire, dated 1960, or the studies of J. Tschauner, dated 1967, can demonstrate. These early works not only are milestones for ...