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The Iranian height datum offset from the GBVP solution and spirit-leveling/gravimetry data / Amir Ebadi in Journal of geodesy, vol 93 n° 8 (August 2019)  

Public [article]  inJournal of geodesy > vol 93 n° 8 (August 2019) . - pp 1207 - 1225 Titre : The Iranian height datum offset from the GBVP solution and spirit-leveling/gravimetry data Type de document : Article/Communication Auteurs : Amir Ebadi, Auteur ; Alireza A. Ardalan, Auteur ; Roohollah Karimi, Auteur Année de publication : 2019 Article en page(s) : pp 1207 - 1225 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique [Termes IGN] analyse de variance [Termes IGN] champ de pesanteur terrestre [Termes IGN] compensation par moindres carrés [Termes IGN] géoïde terrestre [Termes IGN] Iran [Termes IGN] levé gravimétrique [Termes IGN] modèle de géopotentiel [Termes IGN] potentiel de pesanteur terrestre [Termes IGN] problème des valeurs limites [Termes IGN] réseau altimétrique local [Termes IGN] réseau altimétrique national Résumé : (auteur) The gravity potential of the zero point of the Iranian height datum (IRHD) is determined as well as the IRHD offset from a global geoid. For this purpose, the geodetic boundary value problem (GBVP) solution based on the remove–compute–restore (RCR) technique is used. In the RCR technique, a global geopotential model (GGM) is required as a reference to remove and restore the long wavelengths of the gravity field. Since the GGMs do not have adequate accuracy over Iran, the IRHD offset is not precisely estimated by the GBVP solution. In this study, aiming to improve the latter, a combination solution based on the GBVP approach and spirit-leveling/gravimetry (LG) data, called the GBVP_LG solution, is proposed. To obtain the GBVP_LG solution, gravity potential obtained from the GBVP solution and the gravity potential differences derived from the LG data are used as two types of observations in a least-squares adjustment. The proper relative weight matrices are determined using the variance component estimation method. To evaluate the proposed method, the gravity potential differences between the start and end points of several check-lines in the leveling network derived from the GBVP and GBVP_LG solutions are compared with those of the LG data. The results show that the dependency of the GBVP_LG solution on the reference model used is much less than that of the GBVP solution. In addition, the results indicate that the GBVP_LG solution has a 42% improvement with respect to the GBVP solution in terms of root-mean-square error. As a result of the GBVP_LG solution, the gravity potential of the IRHD zero point is estimated equal to WIRHD0=62,636,855.89±0.16m2/s2. Therefore, the IRHD offset with respect to the geoid defined by W0=62,636,853.4m2/s2 is obtained equal to −25.4±1.6cm, which means that the IRHD is 25.4 cm below the geoid. Numéro de notice : A2019-385 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-019-01237-x Date de publication en ligne : 12/02/2019 En ligne : https://doi.org/10.1007/s00190-019-01237-x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=93464 [article]

On constrained integrated total Kalman filter for integrated direct geo-referencing / Vahid Mahboub in Survey review, vol 51 n° 364 (January 2019)  

Public [article]  inSurvey review > vol 51 n° 364 (January 2019) . - pp 26 - 34 Titre : On constrained integrated total Kalman filter for integrated direct geo-referencing Type de document : Article/Communication Auteurs : Vahid Mahboub, Auteur ; Mohammad Saadatseresht, Auteur ; Alireza A. Ardalan, Auteur Année de publication : 2019 Article en page(s) : pp 26 - 34 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement du signal [Termes IGN] filtrage du bruit [Termes IGN] filtre de Kalman [Termes IGN] géoréférencement direct [Termes IGN] GPS-INS [Termes IGN] invariant [Termes IGN] matrice de covariance [Termes IGN] modèle dynamique Résumé : (Auteur) A constrained integrated total Kalman filter algorithm is developed. It considers a quadratic constraint which may appear in some problems of integrated direct geo-referencing in particular when INS data is used as system equations of a Kalman filter algorithm. In such a case one encounters with a dynamic errors-in-variables (DEIV) model for system equations, although DEIV model has been already considered for equations of the Kalman filter algorithm and a solution namely integrated total Kalman filter (ITKF) has been given to it. Also this algorithm can be simplified to unconstraint case which is useful for some problems. It considers DEIV model for both observation equations and system equations of the Kalman filter algorithm. The predicted residuals for all variables including the random noise at the first epoch, the observational noise, the random system noise and the corresponding noise of two coefficient matrixes (in the system equations and the observation equations) besides the variance matrix of the unknown parameters are obtained. In two numerical examples, integrated direct geo-referencing problem is solved for a GPS-INS system. Numéro de notice : A2019-186 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/00396265.2017.1341736 Date de publication en ligne : 30/06/2017 En ligne : https://doi.org/10.1080/00396265.2017.1341736 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=92617 [article]

A bias-free geodetic boundary value problem approach to height datum unification / Alireza A. Ardalan in Journal of geodesy, vol 84 n° 2 (February 2010)  

Public [article]  inJournal of geodesy > vol 84 n° 2 (February 2010) . - pp 123 - 134 Titre : A bias-free geodetic boundary value problem approach to height datum unification Type de document : Article/Communication Auteurs : Alireza A. Ardalan, Auteur ; R. Karimi, Auteur ; Markku Poutanen, Auteur Année de publication : 2010 Article en page(s) : pp 123 - 134 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique [Termes IGN] cote géopotentielle [Termes IGN] erreur systématique [Termes IGN] Finlande [Termes IGN] géoïde local [Termes IGN] hauteur ellipsoïdale [Termes IGN] problème des valeurs limites [Termes IGN] réseau altimétrique local [Termes IGN] système de référence altimétrique Résumé : (Auteur) A geodetic boundary value problem (GBVP) approach has been formulated which can be used for solving the problem of height datum unification. The developed technique is applied to a test area in Southwest Finland with approximate size of 1.5° x 3° and the bias of the corresponding local height datum (local geoid) with respect to the geoid is computed. For this purpose the bias-free potential difference and gravity difference observations of the test area are used and the offset (bias) of the height datum, i.e., Finnish Height Datum 2000 (N2000) fixed to Normaal Amsterdams Peil (NAP) as origin point, with respect to the geoid is computed. The results of this computation show that potential of the origin point of N2000, i.e., NAP, is (62636857.68 1 0.5) (m2/s2) and as such is (0.191 1 0.003) (m) under the geoid defined by W 0 = 62636855.8 (m2/s2). As the validity test of our methodology, the test area is divided into two parts and the corresponding potential difference and gravity difference observations are introduced into our GBVP separately and the bias of height datums of the two parts are computed with respect to the geoid. Obtaining approximately the same bias values for the height datums of the two parts being part of one height datum with one origin point proves the validity of our approach. Besides, the latter test shows the capability of our methodology for patch-wise application. Copyright Springer Numéro de notice : A2010-107 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-009-0348-8 Date de publication en ligne : 10/10/2009 En ligne : https://doi.org/10.1007/s00190-009-0348-8 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30303 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
266-2010021	SL	Revue	Centre de documentation	Revues en salle	Disponible

Global height datum unification : a new approach in gravity potential space / Alireza A. Ardalan in Journal of geodesy, vol 79 n° 9 (December 2005)  

Public [article]  inJournal of geodesy > vol 79 n° 9 (December 2005) . - pp 512 - 523 Titre : Global height datum unification : a new approach in gravity potential space Type de document : Article/Communication Auteurs : Alireza A. Ardalan, Auteur ; A. Safari, Auteur Année de publication : 2005 Article en page(s) : pp 512 - 523 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique [Termes IGN] géoïde terrestre [Termes IGN] International Terrestrial Reference System [Termes IGN] Iran [Termes IGN] levé gravimétrique [Termes IGN] niveau moyen des mers [Termes IGN] ondelette d'Abel-Poisson [Termes IGN] positionnement par GNSS [Termes IGN] potentiel de pesanteur terrestre [Termes IGN] problème des valeurs limites [Termes IGN] système de référence altimétrique [Termes IGN] système de référence local Résumé : (Auteur) The problem of "global height datum unification" is solved in the gravity potential space based on: (1) high-resolution local gravity field modeling, (2) geocentric coordinates of the reference benchmark, and (3) a known value of the geoid's potential. The high-resolution local gravity field model is derived based on a solution of the fixed-free two-boundary-value problem of the Earth's gravity field using (a) potential difference values (from precise leveling), (b) modulus of the gravity vector (from gravimetry), (c) astronomical longitude and latitude (from geodetic astronomy and/or combination of (GNSS) Global Navigation Satellite System observations with total station measurements), (d) and satellite altimetry. Knowing the height of the reference benchmark in the national height system and its geocentric GNSS coordinates, and using the derived high-resolution local gravity field model, the gravity potential value of the zero point of the height system is computed. The difference between the derived gravity potential value of the zero point of the height system and the geoid's potential value is computed. This potential difference gives the offset of the zero point of the height system from geoid in the "potential space", which is transferred into "geometry space" using the transformation formula derived in this paper. The method was applied to the computation of the offset of the zero point of the Iranian height datum from the geoid's potential value W0=62636855.8 m 2/S2 . According to the geometry space computations, the height datum of Iran is 0.09 m below the geoid. Numéro de notice : A2005-518 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-005-0001-0 En ligne : https://doi.org/10.1007/s00190-005-0001-0 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27654 [article]

Exemplaires(2)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
266-05091	RAB	Revue	Centre de documentation	En réserve L003	Disponible
266-05092	RAB	Revue	Centre de documentation	En réserve L003	Disponible