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Official GNSS-derived vertical orthometric height control network / G. Steinberg in SaLIS Surveying and land information science, vol 68 n° 1 (March 2008)
[article]
Titre : Official GNSS-derived vertical orthometric height control network Type de document : Article/Communication Auteurs : G. Steinberg, Auteur ; Gilad Even-Tzur, Auteur Année de publication : 2008 Article en page(s) : pp 29 - 34 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] altitude orthométrique
[Termes IGN] conversion altimétrique
[Termes IGN] géoïde local
[Termes IGN] hauteur ellipsoïdale
[Termes IGN] Israël
[Termes IGN] nivellement par GPS
[Termes IGN] positionnement par GNSS
[Termes IGN] réseau de nivellement
[Vedettes matières IGN] AltimétrieRésumé : (Auteur) Since the beginning of 2006, the vertical control system in Israel has been ellipsoidal. The Survey of Israel (SOI) will not continue with nationwide precise leveling. Instead, data from permanent Global Navigation Satellite Systems (GNSS) stations are used to develop and maintain Israel's ellipsoidal vertical control system. Currently, the objective is to provide a framework on which topographers and engineers can base and adjust their heights, and this is achieved more easily by GNSS measurements. Despite this, many users of height data prefer the orthometric system, even though its control is localized. A geoid undulation model is one of the foundations of the geodetic infrastructure. It is used to connect ellipsoidal and orthometric heights. Intensive utilization of GNSS for geodetic, surveying and engineering applications necessitates the development of an undulation model. Efforts to develop such a model with an accuracy level of 1 centimeter over an entire country demand multiple resources. This paper suggests a method for developing a national, orthometric control system with a reasonable accuracy, using GNSS measurements, ellipsoidal vertical control, and an official geoid undulation model. Research was conducted in Israel in order to test the feasibility of using an official geoid undulation model. Two kinds of official models were tested: the worldwide geopotential model (GPM98B) and a local, countrywide model computed by the Survey of Israel. We compared orthometric height differences obtained by GPS measurements with the known orthometric differences. This paper presents the results of those experiments. The technique proposed in this paper was found to define seamless orthometric vertical control adequate for most geodetic and surveying purposes, at low cost and fast. Of special interest in the paper is the comparison between the proposed idea and the National Geodetic Survey (NGS) attitude toward GPS-derived orthometric heights. The advantage of using the official geoid undulation model for the acquisition of orthometric heights is demonstrated. Copyright SaLIS Numéro de notice : A2008-267 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83664
in SaLIS Surveying and land information science > vol 68 n° 1 (March 2008) . - pp 29 - 34[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 121-08011 RAB Revue Centre de documentation En réserve L003 Disponible On the non-uniqueness of local quasi-geoids computed from terrestrial gravity anomalies / I. Prutkin in Journal of geodesy, vol 82 n° 3 (March 2008)
[article]
Titre : On the non-uniqueness of local quasi-geoids computed from terrestrial gravity anomalies Type de document : Article/Communication Auteurs : I. Prutkin, Auteur ; R. Klees, Auteur Année de publication : 2008 Article en page(s) : pp 147 - 156 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] anomalie de pesanteur
[Termes IGN] champ de pesanteur local
[Termes IGN] données GPS
[Termes IGN] géoïde local
[Termes IGN] nivellement par GPSRésumé : (Auteur) We consider the problem of local (quasi-)geoid modelling from terrestrial gravity anomalies. Whereas this problem is uniquely solvable (up to spherical harmonic degree one) if gravity anomalies are globally available, the problem is non-unique if gravity anomalies are only available within a local area, which is the typical situation in local/regional gravity field modelling. We derive a mathematical description of the kernel of the gravity anomaly operator. The non-uniqueness can be removed using external height anomaly information, e.g., provided by GPS-levelling. The corresponding problem is formulated as a Cauchy problem for the Laplace equation. The existence and uniqueness of the solution of the Cauchy problem is guaranteed by the Cauchy–Kowalevskaya theorem. We propose several numerical procedures to compute the solution of the Cauchy problem from given differences between gravimetric and geometric height anomalies. We apply the numerical techniques to real data over the Netherlands and Germany. We show that we can compute a unique quasi-geoid from observed gravimetric and geometric height anomalies, which agree with the data within the expected noise level. We conclude that observed differences between gravimetric height anomalies and geometric height anomalies derived from GPS and levelling cannot only be attributed to systematic errors in the data sets, but are also caused by the intrinsic non-uniqueness of the problem of local quasi-geoid modelling from gravity anomalies. Hence, GPS-levelling data are necessary to get a unique solution, which also implies that they should not be used to validate local quasi-geoid solutions computed on the basis of gravity anomalies. Copyright Springer Numéro de notice : A2008-166 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-007-0161-1 En ligne : https://doi.org/10.1007/s00190-007-0161-1 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29161
in Journal of geodesy > vol 82 n° 3 (March 2008) . - pp 147 - 156[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 266-08031 RAB Revue Centre de documentation En réserve L003 Disponible 266-08032 RAB Revue Centre de documentation En réserve L003 Disponible Effects of topographic-isostatic masses on gravitational functionals at the Earth's surface and at airborne and satellite altitudes / A. Makhloof in Journal of geodesy, vol 82 n° 2 (February 2008)
[article]
Titre : Effects of topographic-isostatic masses on gravitational functionals at the Earth's surface and at airborne and satellite altitudes Type de document : Article/Communication Auteurs : A. Makhloof, Auteur ; K.H. Ilk, Auteur Année de publication : 2008 Article en page(s) : pp 93 - 111 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] champ de pesanteur local
[Termes IGN] force de gravitation
[Termes IGN] gravimétrie aérienne
[Termes IGN] gravimétrie spatiale
[Termes IGN] isostasie
[Termes IGN] pesanteur terrestre
[Termes IGN] reliefRésumé : (Auteur) Topographic–isostatic masses represent an important source of gravity field information, especially in the high-frequency band, even if the detailed mass-density distribution inside the topographic masses is unknown. If this information is used within a remove-restore procedure, then the instability problems in downward continuation of gravity observations from aircraft or satellite altitudes can be reduced. In this article, integral formulae are derived for determination of gravitational effects of topographic–isostatic masses on the first- and second-order derivatives of the gravitational potential for three topographic–isostatic models. The application of these formulas is useful for airborne gravimetry/gradiometry and satellite gravity gradiometry. The formulas are presented in spherical approximation by separating the 3D integration in an analytical integration in the radial direction and 2D integration over the mean sphere. Therefore, spherical volume elements can be considered as being approximated by mass-lines located at the centre of the discretization compartments (the mass of the tesseroid is condensed mathematically along its vertical axis). The errors of this approximation are investigated for the second-order derivatives of the topographic–isostatic gravitational potential in the vicinity of the Earth’s surface. The formulas are then applied to various scenarios of airborne gravimetry/gradiometry and satellite gradiometry. The components of the gravitational vector at aircraft altitudes of 4 and 10 km have been determined, as well as the gravitational tensor components at a satellite altitude of 250 km envisaged for the forthcoming GOCE (gravity field and steady-state ocean-circulation explorer) mission. The numerical computations are based on digital elevation models with a 5-arc-minute resolution for satellite gravity gradiometry and 1-arc-minute resolution for airborne gravity/gradiometry. Copyright Springer Numéro de notice : A2008-044 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-007-0159-8 En ligne : https://doi.org/10.1007/s00190-007-0159-8 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29039
in Journal of geodesy > vol 82 n° 2 (February 2008) . - pp 93 - 111[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 266-08022 RAB Revue Centre de documentation En réserve L003 Disponible 266-08021 RAB Revue Centre de documentation En réserve L003 Disponible GOCE : obtaining a portrait of Earth's most intimate features / M. Drinkwater in ESA bulletin, n° 133 (February 2008)
[article]
Titre : GOCE : obtaining a portrait of Earth's most intimate features Type de document : Article/Communication Auteurs : M. Drinkwater, Auteur ; Roger Haagmans, Auteur ; M. Kern, Auteur ; et al., Auteur Année de publication : 2008 Article en page(s) : pp 4 - 13 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Missions spatiales
[Termes IGN] circulation océanique
[Termes IGN] données GOCE
[Termes IGN] géoïde
[Termes IGN] GOCE
[Termes IGN] gradiomètre
[Termes IGN] levé gravimétrique
[Termes IGN] nivellement
[Termes IGN] satellite d'observation de la TerreRésumé : (Auteur) Known as ESA's "Gravity Mission", GOCE represent a blend of revolutionary new technology, designed to open a new chapter in what has historically been one of the most intriguing issues confronting science. Scheduled for launch in mid-2008, Goce will deliver data about the fundamental force of nature, which will benefit a broad range of applications in Earth sciences. Copyright European Space Agency Numéro de notice : A2008-124 Affiliation des auteurs : non IGN Thématique : IMAGERIE/POSITIONNEMENT Nature : Article DOI : sans En ligne : http://www.esa.int/esapub/bulletin/bulletin133/bul133b_drinkwater.pdf Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29119
in ESA bulletin > n° 133 (February 2008) . - pp 4 - 13[article]GOCE's measurements of the gravity field and beyond / R. Floberghaben in ESA bulletin, n° 133 (February 2008)
[article]
Titre : GOCE's measurements of the gravity field and beyond Type de document : Article/Communication Auteurs : R. Floberghaben, Auteur ; M. Drinkwater, Auteur ; Roger Haagmans, Auteur ; M. Kern, Auteur Année de publication : 2008 Article en page(s) : pp 24 - 31 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] champ de pesanteur terrestre
[Termes IGN] circulation océanique
[Termes IGN] GOCE
[Termes IGN] gradient de gravitation
[Termes IGN] levé gravimétrique
[Termes IGN] niveau moyen des mersRésumé : (Auteur) Ocean circulation, sea level rise and the ocean's role as a regulator of climate are just some of the critical phenomena that can be further studied with the help of GOCE's gravity field products. But how do the spacecraft's measurements become part of this new information source? Copyright European Space Agency Numéro de notice : A2008-125 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans En ligne : http://www.esa.int/esapub/bulletin/bulletin133/bul133d_floberghagen.pdf Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29120
in ESA bulletin > n° 133 (February 2008) . - pp 24 - 31[article]Analyse des séries temporelles de positions des stations de géodésie spatiale : application au repère international de référence terrestre (ITRF) / Xavier Collilieux (2008)PermalinkPermalinkGeometrical geodesy / M. Hooijberg (2008)PermalinkPermalinkRapport du directeur sur l'activité et la gestion du Bureau International des Poids et Mesures (BIPM), 1er juillet 2007 - 30 juin 2008 / Bureau international des poids et mesures (2008)PermalinkPermalinkPermalinkVers un futur repère de référence céleste : Journées 2007, systèmes de référence spatio-temporels, Paris, 17-19 septembre 2007 / Nicole Capitaine (2008)Permalink350 first order points selected: creation of a geodetic reference frame in WGS-84 datum for Cartosat in India / K.S. Rao in Geoinformatics, vol 10 n° 8 (01/12/2007)PermalinkLe Quasi-géoïde libanais (QGL06) et la référence d'altitude du NGL (RAL 06) / Mohamed Allouche in XYZ, n° 113 (décembre 2007 - février 2008)PermalinkCoseismic and post-seismic signatures of the Sumatra 2004 December and 2005 March earthquakes in GRACE satellite gravity / Isabelle Panet in Geophysical journal international, vol 171 n° 1 (Octobre 2007)PermalinkITRF2005: A new release of the International Terrestrial Reference Frame based on time series of station positions and Earth Orientation Parameters / Zuheir Altamimi in Journal of geophysical research : Solid Earth, vol 112 n° 9 (September 2007)PermalinkPractical geodesy: part 5 chart projections / Huibert-Jan Lekkerkerk in Geoinformatics, vol 10 n° 6 (01/09/2007)PermalinkQuasigeoid evaluation with improved levelled height data for Norway / D.I. Lysaker in Journal of geodesy, vol 81 n° 9 (September 2007)PermalinkGeneration of study of high-resolution satellite gravity over the Sumatra earthquake region / Samprit Chatterjee in International Journal of Remote Sensing IJRS, vol 28 n° 13-14 (July 2007)PermalinkCombined Earth orientation parameters based on homogeneous and continuous VLBI and GPS data / Daniela Thaller in Journal of geodesy, vol 81 n° 6-8 (June - August 2007)PermalinkPractical geodesy: part 3 The geoid / Huibert-Jan Lekkerkerk in Geoinformatics, vol 10 n° 4 (01/06/2007)PermalinkAnalysis of a possible future degradation in the DORIS geodetic results related to changes in the satellite constellation / Pascal Willis in Advances in space research, vol 39 n° 10 (May 2007)PermalinkA comparison of GPS, VLBI and model estimates of ocean tide loading displacements / I.D. Thomas in Journal of geodesy, vol 81 n° 5 (May 2007)PermalinkDORIS satellite phase center determination and consequences on the derived scale of the Terrestrial Reference Frame / Pascal Willis in Advances in space research, vol 39 n° 10 (May 2007)Permalink