scholarly journals The normal gravity formula and the polar flattening according to geodetic reference system 1967

2011 ◽  
Vol 21 (1) ◽  
Author(s):  
M. CAPUTO ◽  
L. PIERI
Keyword(s):  
Reference System ◽  
Normal Gravity ◽  
Geodetic Reference System

scholarly journals Correction to: High-fidelity elastic Green’s functions for subduction zone models consistent with the global standard geodetic reference system

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Takane Hori ◽  
Ryoichiro Agata ◽  
Tsuyoshi Ichimura ◽  
Kohei Fujita ◽  
Takuma Yamaguchi ◽  
...  
Keyword(s):  
Subduction Zone ◽  
Reference System ◽  
Green's Functions ◽  
Green’S Functions ◽  
Geodetic Reference System ◽  
High Fidelity

An amendment to this paper has been published and can be accessed via the original article.

scholarly journals The 1964 IAU System and the Geodetic Reference System 1967

1971 ◽  
Vol 9 ◽  
pp. 279-280
Author(s):  
J. Kovalevsky
Keyword(s):  
Gravitational Field ◽  
Reference System ◽  
Geodetic Reference System ◽  
The Earth

In 1964, the IAU adopted, among the primary constants of its system, the following three constants especially related to the shape, dimensions and gravitational field of the Earth:a = 6378160 mGM = 398603 × 109m3/s2J2 = 0.0010827These values were discussed in 1967 by the IAG and adopted by the IUGG as the basis of a ‘Geodetic Reference System 1967’. Although at that time better values of these constants were available, IUGG decided to adopt the values of the IAU system in order to keep consistency with the values agreed upon by the astronomers.

scholarly journals GEODETIC REFERENCE SYSTEM TRANSFORMATIONS OF 3D ARCHIVAL GEOSPATIAL DATA USING A SINGLE SSC TERRASAR-X IMAGE

2016 ◽  
Vol XLI-B1 ◽  
pp. 1207-1212
Author(s):  
D. I. Vassilaki ◽  
A. A. Stamos
Keyword(s):  
Coordinate System ◽  
Real World ◽  
Reference System ◽  
Absolute Error ◽  
Geospatial Data ◽  
Geodetic Reference System ◽  
Coordinate Systems ◽  
3D Information ◽  
The Relationship ◽  
Geolocation Accuracy

Many older maps were created using reference coordinate systems which are no longer available, either because no information to a datum was taken in the first place or the reference system is forgotten. In other cases the relationship between the map’s coordinate system is not known with precision, meaning that its absolute error is much larger than its relative error. In this paper the georeferencing of medium-scale maps is computed using a single TerraSAR-X image. A single TerraSAR-X image has high geolocation accuracy but it has no 3D information. The map, however, provides the missing 3D information, and thus it is possible to compute the georeferencing of the map using the TerraSAR-X geolocation information, assembling the information of both sources to produce 3D points in the reference system of the TerraSAR-X image. Two methods based on this concept are proposed. The methods are tested with real world examples and the results are promising for further research.

scholarly journals High Delity Elastic Green's Functions for Subduction Zone Models Consistent With the Global Standard Geodetic Reference System

2020 ◽  
Author(s):  
Takane Hori ◽  
Ryoichiro Agata ◽  
Tsuyoshi Ichimura ◽  
Kohei Fujita ◽  
Takuma Yamaguchi ◽  
...  
Keyword(s):  
Reference System ◽  
Subduction Zones ◽  
Structural Models ◽  
Tsunami Hazard ◽  
Geodetic Reference System ◽  
Coordinate Systems ◽  
Ellipsoidal Shape ◽  
The Earth ◽  
Hazard Assessments ◽  
Realistic Topography

Abstract Green's functions (GFs) for elastic deformation due to unit slip on the fault plane comprise an essential tool for estimating earthquake rupture and underground preparation processes. These estimation results are often applied to generate important information for public such as seismic and tsunami hazard assessments. So, it is important to minimize the distortion of the estimation results on the numerical models used for calculating GFs to guarantee assessment reliability. For this purpose, we here calculated GFs based on a numerical model that is of high delity to obtain realistic topography and subsurface structural models of the Earth. We targeted two well-known subduction zones in Japan, the Nankai Trough and the Japan Trench. For these subduction zones, databases for realistic topography and subsurface structural models of the Earth are available in the \Japan integrated velocity structure model version 1", which was proposed for earthquake hazard assessments conducted by the Japanese government.Furthermore, in order to eliminate inconsistencies in data processing of the calculated and observed response, we used the same coordinate systems for processing GFs as those adopted widely to process space geodetic observation data for surface displacements. The ellipsoidal shape of the Earth, which is often approximated with a projected plane or a spherical shape, was also incorporated by faithfully following the denitions of the coordinate systems in Geodetic Reference System 1980, which is the global standard for space geodesy. To calculate elastic GFs based on such high delity subduction zone databases with the ellipsoidal shape of the Earth, we introduced the nite element (FE) method. In the FE meshes, the resolution of the topography and subsurface structure is the same as that of the original databases. Recent development of the state-of-the-art computation techniques for the rapid calculation of crustal deformation using large-scale FE models allows for GF calculation based on such a high delity model. However, it is generally not easy to perform such calculations. Thus, we released a library for the GFs calculated in this study to the geoscience community on a web server, aiming to contribute more reliable seismic and tsunami hazard assessment.

Deformation detection through the realization of reference frames

2020 ◽  
Vol 14 (2) ◽  
pp. 133-148
Author(s):  
Nestoras Papadopoulos ◽  
Melissinos Paraskevas ◽  
Ioannis Katsafados ◽  
Georgios Nikolaidis ◽  
Euagelos Anagnostou
Keyword(s):  
Reference Frame ◽  
Reference System ◽  
Reference Frames ◽  
Satellite System ◽  
Geodetic Reference System ◽  
Deformation Model ◽  
Navigation Systems ◽  
International Gnss Service ◽  
Tectonically Active ◽  
Global Navigation Satellite

AbstractHellenic Military Geographical Service (HMGS) has established and measured various networks in Greece which constitute the geodetic infrastructure of the country. One of them is the triangulation network consisting of about 26.000 pillars all over Greece. Classical geodetic measurements that held by the Hellenic Military Geographic Service (HMGS) through the years have been used after adjustment for the state reference frame which materializes the current Hellenic Geodetic Reference System of 1987 (HGRS87). The aforementioned Reference System (RS) is a static one and is in use since 1990. Through the years especially in the era of satellite navigation systems many Global Navigation Satellite System (GNSS) networks have been established. The latest such network materialized by HMGS is ongoing and covers until now more than the 2/3 of the country. It is referenced by International GNSS Service (IGS) permanent stations and consists a local densification IGS08 Reference Frame. Firstly, this gives the opportunity to calculate transformation parameters between the two systems and a statistical analysis of the residuals leads to intermediate conclusions. After that and in conjunction with existing past transformations, tectonic deformations and their directions are concluded. Moreover past GPS observations on the same pillars in compare to the newer ones give also a sense of tectonic displacements. Greece is one of the most tectonically active countries in Europe and the adoption of a modern kinematic or semi-kinematic geodetic datum is a necessity as it should incorporate a deformation model like 3d velocities on the reference frame realization. The detection of geodynamic changes is a continuous need and should be taken into consideration at each epoch.

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.

The IGFS gravity field observations and products contributions to GGOS infrastructure

2020 ◽  
Author(s):  
Georgios S. Vergos ◽  
Riccardo Barzaghi ◽  
Sylvaint Bovalot ◽  
Elmas Sinem Ince ◽  
Adrian Jäggi ◽  
...  
Keyword(s):  
Gravity Field ◽  
Reference System ◽  
Earth Tides ◽  
Absolute Gravity ◽  
Geodetic Reference System ◽  
Global Gravity ◽  
Digital Elevation ◽  
Elevation Model ◽  
Global And Local ◽  
The Impact

<p>Through its structure the International Gravity Field Service (IGFS) promotes the interaction, cooperation and synergy between the Gravity Services, namely the Bureau Gravimétrique International (BGI), the International Service for the Geoid (ISG), the International Geodynamics and Earth Tides Service (IGETS), the International Center for Global Earth Models (ICGEM), the International Combination Service for Time-variable Gravity Fields (COST-G) and the International Digital Elevation Model Service (IDEMS).</p><p>Furthermore, via its Central Bureau hosted at the Aristotle University of Thessaloniki (Greece), IGFS provides a link to the Global Geodetic Observing System (GGOS) Bureaus in order to communicate their requirements and recommendations to the IGFS-Centers. Moreover, IGFS provides a coordination host for the utilization of gravity-field related products and services towards their inclusion within a GGOS consistent frame meeting the necessary precision and accuracy requirements.</p><p>In this work, an outline is given on the recent activities of IGFS, namely those related to the contributions to the implementation of: the International Height Reference System/Frame; the Global Geodetic Reference System/Frame; the new Global Absolute Gravity Reference System/Frame and rhe combination of temporal monthly global gravity field models. Particularly, the impact that these activities have and will have in improving the estimation of the Earth’s gravity field, either at global and local scale, is highlighted also in the framework of GGOS.</p>

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.

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