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Fundamental gravity network of the Republic Croatia in the function of control and improving of national and European geoid model / I. Grgic (01/01/2010)

Public contenu dans Second proceedings of the Croatian Geodetic Institute for the period 2006-2009 / Croatian geodetic institute (2010) Titre : Fundamental gravity network of the Republic Croatia in the function of control and improving of national and European geoid model Type de document : Article/Communication Auteurs : I. Grgic, Auteur ; B. Barisic, Auteur ; Tomislav Basic, Auteur ; et al., Auteur Editeur : Zagreb [Croatie] : Croatian geodetic institute Année de publication : 01/01/2010 Conférence : CGI 2009, 2nd proceedings of the Croatian Geodetic Institute for the period 2006-2009 Zagreb Croatie Importance : pp 82 - 94 Note générale : Bibliographie Langues : Anglais (eng) Serbo-croate (Latin) (scr) Descripteur : [Vedettes matières IGN] Géodésie physique [Termes IGN] Croatie [Termes IGN] European vertical GPS reference network [Termes IGN] géoïde local Résumé : (Auteur) By demand for densification of EUVN_DA network with additional points on state territory, Republic Croatia is again activated in project EUVN_DA on national level in year 2005. During project EUVN_DA network is expanded from 8 existing points to 20 points. Difference between EGG97 and EUVN model showed possible errors on some areas or points (HR05 Split). Therefore, those errors were eliminated by measurements and results were free of errors from first EUVN campaign in year 1997. Differences between national model of geoid HRG2000 and EUVN show better adjustment of geoid surface for state area than continen-tal EGG97 geoid. Therefore they are additional control in densification of EUVN_DA project. Result analysis along coast showed large differences between geoid models. From the old gravi-ty network (84 gravity points) 25 gravity points were used. After stabilization of 11 new gravity points Basic Gravity Network comprises 36 gravity points. Finalization of establishment of the Fundamental Gravity Network of the Republic of Croatia is also planned to improve absolute national geoid orientation. As well, EUVN points in Croatia, based on Fundamental Gravity Network, will ensure better identification of geoid differences on continental level. Numéro de notice : C2007-004 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Communication DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=65035

Preliminary works on creation of the new geoid model HRG2009 / I. Grgic (01/01/2010)

Public contenu dans Second proceedings of the Croatian Geodetic Institute for the period 2006-2009 / Croatian geodetic institute (2010) Titre : Preliminary works on creation of the new geoid model HRG2009 Type de document : Article/Communication Auteurs : I. Grgic, Auteur ; M. Lucic, Auteur ; Marija Repanic, Auteur ; et al., Auteur Editeur : Zagreb [Croatie] : Croatian geodetic institute Année de publication : 01/01/2010 Conférence : CGI 2009, 2nd proceedings of the Croatian Geodetic Institute for the period 2006-2009 Zagreb Croatie Importance : pp 303 - 312 Note générale : Bibliographie Langues : Anglais (eng) Serbo-croate (Latin) (scr) Descripteur : [Vedettes matières IGN] Géodésie physique [Termes IGN] Croatie [Termes IGN] géoïde altimétrique [Termes IGN] géoïde local [Termes IGN] nivellement [Termes IGN] positionnement par GNSS Résumé : (Auteur) The official Croatian geoid model HRG2000 was developed as a surface for con--version of GNSS-derived ellipsoidal heights into orthometric heights. CROatian POsitionig System (CROPOS), based on 30 permanently working GNSS reference station, had been esta-blished last year. Since HRG2000 geoid model characterizes some weaknesses regarding abso-lute orientation we have used CROPOS service to define new points which will be a base for creation of the new Croatian geiod model HRG2009. For this purpose over the whole Croatian territory more than 500 GNSS/levelling geodetic points were stabilized and measured according to the approximate raster of10x10km. All measured points were connected to the nearest ben-chmarks of the new Croatian vertical datum by precise levelling. The GNSS/Levelling survey provides reliable geoid undulation but only at the points where the survey is made. Therefore for the construction of an accurate HRG2009 geoid model afterwards the gravimetric geo-id model, which should be calculated from all new measured gravity points and old availa-ble gravity data, will befitted to the geoid undulation data from a GNSS/levelling survey. The recently determined geoid undulation calculated from GNSS/Levelling data at the measured geodetic points were analyzed additionally in relation to the geoid undulation from the geoid model HRG2000. The range of geoid undulation and orthometric height differences at measu-red points between old and new geoid model shows an important progress concerning quality in definition of heights for the Republic of Croatia. Numéro de notice : C2009-014 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Communication Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=65054