scholarly journals Comparison between Astronomical and Geodetic Coordinates

1991 ◽  
Vol 127 ◽  
pp. 210-210
Author(s):  
A. Banni ◽  
A. Poma ◽  
E. Proverbio ◽  
E. Falchi ◽  
F. Resta ◽  
...  
Keyword(s):  
Earth Rotation ◽  
Reference System ◽  
Temporal Variations ◽  
Coordinate Frame ◽  
Local Conditions ◽  
Geodetic Coordinates ◽  
Terrestrial Reference System ◽  
Definition Of

A requirement for solving Earth rotation problems is the definition of a terrestrial reference system (or systems) and the determination of a terrestrial coordinate frame (or frames). In this context it is important to determine the positions of the observing sites and their temporal variations and establish the dependence of the observations on local conditions and observing methods.In situ concurrent observations are therefore important. In this paper we report the results of a comparison between astronomical and geodetic coordinates derived from different observations at the Cagliari Observatory and the Carloforte latitude station.

scholarly journals A Terrestrial Reference System Consistent with WGRS

1991 ◽  
Vol 127 ◽  
pp. 211-214 ◽  
Author(s):  
C. Boucher ◽  
Z. Altamimi
Keyword(s):  
Reference System ◽  
Terrestrial Reference Frame ◽  
Reference Systems ◽  
International Earth Rotation Service ◽  
Earth Orientation Parameters ◽  
Terrestrial Reference System ◽  
Definition Of ◽  
Orientation Parameters ◽  
Evolution With Time

AbstractThe IAU and IUGG has jointly established in 1988 an International Earth Rotation Service (IERS) which is in charge of the realization of conventional celestial and terrestrial reference systems, together with the determination of earth orientation parameters which connect them.The theoretical definition of the terrestrial reference system which is realized by IERS through a conventional terrestrial reference frame formed by SLR, LLR, VLBI and GPS stations is presented. In particular its origin, scale, orientation and evolution with time are reviewed, taking into account relativistic and deformation effects.

scholarly journals Selective Fiscal Measures and the Definition of the Relevant Reference Framework in the Light of Cases C‑106/09 P, Commission v Gibraltar and C‑203/16 P, Heitkamp BauHolding v Commission

2020 ◽  
Vol 13 (2) ◽  
pp. 64-75
Author(s):  
Hanna-Mari Immonen
Keyword(s):  
Reference System ◽  
European Court Of Justice ◽  
Tax System ◽  
Reference Framework ◽  
Court Of Justice ◽  
European Court ◽  
Relevant Reference ◽  
Definition Of ◽  
State Aids

This article examines fiscal State aids and the selectivity condition. Assessing the selectivity is relatively complex in tax matters since it involves the analysis of the general tax system in which the regime under review applies. The focus of this article is on the selectivity analysis and the analysis of the general tax system i.e. the determination of the relevant reference framework. The definition of the relevant reference framework is still open to various interpretations despite the fact that the European Court of Justice has examined selectivity issues in several cases in the 2000s. The Gibraltar judgement has materially broadened the interpretation of the selectivity condition and the application of Article 107(1) TFEU. The Heitkamp BauHolding judgment confirms the interpretation adopted in the Gibraltar judgement, but also defines the scope of Article 107(1) TFEU in more detail. Yet the offset of the selectivity assessment i.e. the determination of the relevant reference system is still receptive to various interpretations.

scholarly journals Determination of the relationship between Vietnam national coordinate reference system (VN-2000) and ITRS, WGS84 and PZ-90

2019 ◽  
Vol 94 ◽  
pp. 03014
Author(s):  
Hoa Pham Thi ◽  
Dung Nghiem Quoc ◽  
Thu Trinh Thi Hoai ◽  
Huynh Pham The ◽  
Nhung Le Thi
Keyword(s):  
Reference System ◽  
Least Square ◽  
National Coordinate ◽  
Least Square Approach ◽  
International Terrestrial Reference System ◽  
Terrestrial Reference System ◽  
The Common ◽  
Transformation Parameters ◽  
The Relationship

In July 2000, Hanoi-72 reference system was replaced by the Vietnam reference system, namely as VN-2000 as an official geodetic background system in Vietnam. Ministry of Natural Resources and Environment of Vietnam has reported the transformation parameters between VN-2000 and WGS84. Nevertheless, there is a need to estimate a new transformation parameter set between VN-2000 and WGS84 because WGS84 has been updated. In addition, there is now a lack of an accurate published set of parameters for transformation from VN-2000 to not only the International Terrestrial Reference System ITRS but also PZ-90. In this study, coordinate transformation parameters between ITRS and VN-2000 are estimated through the use of a least square approach and the common points with known coordinates in both systems. These set of parameters was then deployed to determine the link between VN-2000 and WGS84 as well as PZ-90. The results denoted that the derived transformation parameters, on the basis of the results at the checkpoints, could generated station positions with the accuracy at several cm level for transformation from VN-2000 to the new realizations of ITRS, WGS84 and PZ90 and reversely. These achievements reveals that the set of parameters is great significance for many applications related to positioning in Vietnam.

scholarly journals Revisiting Field Capacity (FC): variation of definition of FC and its estimation from pedotransfer functions

2014 ◽  
Vol 38 (6) ◽  
pp. 1750-1764 ◽  
Author(s):  
Theophilo Benedicto Ottoni Filho ◽  
Marta Vasconcelos Ottoni ◽  
Muriel Batista de Oliveira ◽  
José Ronaldo de Macedo ◽  
Klaus Reichardt
Keyword(s):  
Moisture Content ◽  
Soil Properties ◽  
Field Capacity ◽  
Pedotransfer Functions ◽  
Soil Morphology ◽  
Soil Water Retention ◽  
Input Variables ◽  
Definition Of

Taking into account the nature of the hydrological processes involved in in situ measurement of Field Capacity (FC), this study proposes a variation of the definition of FC aiming not only at minimizing the inadequacies of its determination, but also at maintaining its original, practical meaning. Analysis of FC data for 22 Brazilian soils and additional FC data from the literature, all measured according to the proposed definition, which is based on a 48-h drainage time after infiltration by shallow ponding, indicates a weak dependency on the amount of infiltrated water, antecedent moisture level, soil morphology, and the level of the groundwater table, but a strong dependency on basic soil properties. The dependence on basic soil properties allowed determination of FC of the 22 soil profiles by pedotransfer functions (PTFs) using the input variables usually adopted in prediction of soil water retention. Among the input variables, soil moisture content θ (6 kPa) had the greatest impact. Indeed, a linear PTF based only on it resulted in an FC with a root mean squared residue less than 0.04 m³ m-3 for most soils individually. Such a PTF proved to be a better FC predictor than the traditional method of using moisture content at an arbitrary suction. Our FC data were compatible with an equivalent and broader USA database found in the literature, mainly for medium-texture soil samples. One reason for differences between FCs of the two data sets of fine-textured soils is due to their different drainage times. Thus, a standardized procedure for in situ determination of FC is recommended.

Geodetic reference frames in the Netherlands

2005 ◽  
Author(s):  
Arnoud de Bruijne ◽  
Joop van Buren ◽  
Anton Kösters ◽  
Hans van der Marel
Keyword(s):  
The Netherlands ◽  
Reference System ◽  
Large Scale ◽  
Reference Frames ◽  
Three Dimensional ◽  
Geodetic Reference System ◽  
Geoid Model ◽  
Leading Role ◽  
Definition Of

Unambiguous and homogeneous geodetic reference frames are essential to the proper determination of locations and heights. The reference frames used in the Netherlands are the Rijksdriehoekmeting (RD) for locations and the Normaal Amsterdamse Peil (NAP) for heights. The RD has traditionally been managed by the Kadaster; the NAP by Rijkswaterstaat. The emergence of satellite positioning has resulted in drastic changes to these geodetic reference frames. A surveyor is now offered one instrument, GPS (the Global Positioning System), capable of the simultaneous determination of locations and heights. This is possible by virtue of one three-dimensional geodetic reference system - the European Terrestrial Reference System (ETRS89) - which in the Netherlands is maintained in a collaborative arrangement between the Kadaster and Rijkswaterstaat. GPS has been advanced as a practical measurement technique by linking the definition of the RD grid to ETRS89. Nevertheless the introduction of GPS also revealed distortions in the RD grid, which are modelled in the RDNAPTRANSTM2004 transformation. Furthermore, the use of the geoid model has become essential to the use of GPS in determining the height in comparison to NAP. Subsidence that has disrupted the backbone of the NAP gave cause to the need for a large-scale adjustment of the heights of the underground benchmarks and, in so doing, of the grid. Consequently new NAP heights have been introduced at the beginning of 2005; a new definition of the RD grid that had already been introduced in 2000 was once again modified in 2004. During the past few years two NCG subcommissions have devoted a great deal of time to these modifications. This publication lays down ETRS89, the RD and the NAP, together with their mutual relationships. In addition to reviewing the history of the reference frames and the manner in which they are maintained (including, for example, the use of AGRS.NL as the basis for the Dutch geometric infrastructure), the publication also discusses the status of the frames as at 1 January 2005. This encompasses the realisation of ETRS89 via AGRS.NL, the revision and new definition of the RD grid in 2004, and the new NAP publication in 2005. The publication also describes the mutual relationships between the frames in the modernized RDNAPTRANSTM2004 transformation consisting of the new NLGEO2004 geoid model and a model for the distortions of the RD grid. In conclusion, the publication also devotes attention to the future maintenance of the ETRS89, RD and NAP. The continuity of the link between the traditional frames and the three-dimensional frames is of great importance, and ETRS89 will continue to fulfil this linking role. The GPS base network and AGRS.NL reference stations will increasingly assume the leading role in the maintenance of the RD frame. The maintenance of the NAP will continue to be necessary, although during the coming decades the the primary heights will not need revision. In so doing the high quality of the geodetic reference frames required for their use in actual practice will continue to be guaranteed.

Determination of Generalized Coordinates and Forces for Generation of the Three Dimensional Curves with Torsion by PKM (Parallel Kinematik Machines)

2010 ◽  
Vol 166-167 ◽  
pp. 15-26
Author(s):  
N.V. Orlandea
Keyword(s):  
High Precision ◽  
Reference System ◽  
Three Dimensional ◽  
Control Parameters ◽  
Kinematic Control ◽  
Generalized Coordinates ◽  
Definition Of

The paper describes the definition of a set of generalized coordinates and forces (kinematic control parameters) necessary to satisfy a specific job. Specifically, the generation of a three dimensional curve with torsion described by a Frenet reference system. The method employed to accomplish this task is using the Original ADAMS program alias MCADA. The analysis results indicate that the method can be successfully applied when designing motion simulators; however, there are accuracy restrictions for high precision six axis machining.

Détermination du géoïde astro-gravimétrique par la méthode de collocation par moindres carrés

1974 ◽  
Vol 28 (5) ◽  
pp. 559-567
Author(s):  
Gérard Lachapelle
Keyword(s):  
Least Squares ◽  
Satellite Data ◽  
Reference System ◽  
Reference Ellipsoid ◽  
Geodetic Reference System ◽  
Least Squares Collocation ◽  
Method Of Least Squares ◽  
Definition Of ◽  
Optimum Solution

The method of least squares collocation is briefly outlined. Its application to the determination of the astrogravimetric geoid (in fact, satellite data can be used as well) and the difficulties encountered are discussed. By the use of this method, it is possible to combine all types of geodetic data available in order to obtain an optimum solution for the geoid. It is also possible to determine consistent geodetic parameters necessary for the definition of a geodetic reference system. These parameters include the position of the existing astrogeodetic reference ellipsoid with respect to the geocenter to which the gravimetric and satellite data are referred.

scholarly journals Use of Gravity Measurements in Defining and Realizing Reference Systems for Geodynamics

1980 ◽  
Vol 56 ◽  
pp. 217-223
Author(s):  
J. D. Boulanger ◽  
N. N. Pariisky ◽  
L. P. Pellinen
Keyword(s):  
Reference System ◽  
Reference Ellipsoid ◽  
Reference Points ◽  
Sufficient Information ◽  
Reference Systems ◽  
The Earth ◽  
Gravity Measurements ◽  
Terrestrial Reference System

AbstractSingle measurements of gravity cannot give sufficient information about the position of measuring points with respect to some terrestrial reference system. Only a set of gravimetric stations all over the Earth combined with a determination of their coordinates allows one to determine (from the solution of Molodensky’s problem) the heights of these stations with respect to a level ellipsoid with center at the geocenter. Given in addition their heights above some reference ellipsoid, whose position in the Earth’s body is fixed through a set of reference points on its surface, the position of the geocenter in the same reference system may be obtained.

scholarly journals Nutation and reference frame

1995 ◽  
Vol 10 ◽  
pp. 228-231
Author(s):  
N. Capitaine
Keyword(s):  
Perturbation Theory ◽  
Reference Frame ◽  
Euler Equations ◽  
Coordinate Transformation ◽  
Earth Rotation ◽  
Reference System ◽  
Reference Frames ◽  
Fundamental Importance ◽  
Terrestrial Reference System ◽  
Celestial Reference System

The reference frames are of fundamental importance in all kinds of the precession and nutation studies involving the theory, the coordinate transformation and the observations. The aim of this paper is to review all the frames used in such studies and to lead to a better consistency between them in order that theory and reductions of observations be referred, as close as possible, to the frames to which observables are actually sensitive.The equations of Earth rotation can be expressed either as Euler equations in the Terrestrial Reference System (TRS), or as perturbation theory in the Celestial Reference System (CRS) (Kinoshita 1977). Euler equations are transformed to the CRS in the astronomical approach (Woolard 1953) and solved by the method of variation of the parameters, whereas, in the geophysical approach (Melchior 1971), the solutions, first obtained in the TRS, are transformed to the CRS and then solved by an integration with respect to time.

scholarly journals Departure Point, Earth's Rate of Rotation and Coordinate Transformation in Quasi-Inertial Geocentric Equatorial Coordinate System (QIGECS)

1993 ◽  
Vol 156 ◽  
pp. 363-369
Author(s):  
H.J. Yan ◽  
E. Groten
Keyword(s):  
Coordinate Transformation ◽  
Reference System ◽  
Main Part ◽  
Maximum Amplitude ◽  
Additional Term ◽  
Departure Point ◽  
Similar Term ◽  
Terrestrial Reference System ◽  
Definition Of ◽  
Right Ascension

The paper summarizes the discussion on the origin of right-ascension and puts forward new arguments in view of high-precision Geodesy and Astrometry. From the movement of the Celestial Departure Point, the classical right-ascension precession might be amended by an additional term −0s.000257/century originating from the nutation-precession interaction movement. A similar term might also be introduced in the maintenance of a terrestrial reference system, while the concept of a Terrestrial Departure Point is considered. The definition of the Earth's rate of rotation in an inertial or quasi-inertial system is reviewed. A periodic erroneous term of maximum amplitude 2.65mas is pointed out in the conventional transfer relation between CRS and TRS, that can for its main part be compensated by introducing the periodic terms of Woolard's equation of the equinox.

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