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Auteur Andrew Carey Ruffhead |
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Partitions of normalised multiple regression equations for datum transformations / Andrew Carey Ruffhead in Boletim de Ciências Geodésicas, vol 28 n° 1 ([01/03/2022])
[article]
Titre : Partitions of normalised multiple regression equations for datum transformations Type de document : Article/Communication Auteurs : Andrew Carey Ruffhead, Auteur Année de publication : 2022 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] Australie occidentale (Australie)
[Termes IGN] Grande-Bretagne
[Termes IGN] régression multiple
[Termes IGN] Slovénie
[Termes IGN] transformation de coordonnéesRésumé : (auteur) Multiple regression equations (MREs) provide an empirical direct method of transforming coordinates between geodetic datums. Since they offer a means of modelling distortions, they are capable of a more accurate fit to datum-shift datasets than more basic direct methods. MRE models of datum shifts traditionally consist of polynomials based on relative latitude and longitude. However, the limited availability of low-power terms often leads to high-power terms being included, and these are a potential cause of instability. This paper introduces three variations based on simple partitions and 2 or 4 smoothly conjoined polynomials. The new types are North/South, East/West and Four-Quadrant. They increase the availability of low-order terms, enabling distortions to be modelled with fewer side effects. Case studies in Great Britain, Slovenia and Western Australia provide examples of partitioned MREs that are more accurate than conventional MREs with the same number of terms. Numéro de notice : A2022-684 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueNat DOI : sans En ligne : https://revistas.ufpr.br/bcg/article/view/86199/46467 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=101548
in Boletim de Ciências Geodésicas > vol 28 n° 1 [01/03/2022][article]Introduction to multiple regression equations in datum transformations and their reversibility / Andrew Carey Ruffhead in Survey review, vol 50 n° 358 (January 2018)
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Titre : Introduction to multiple regression equations in datum transformations and their reversibility Type de document : Article/Communication Auteurs : Andrew Carey Ruffhead, Auteur Année de publication : 2018 Article en page(s) : pp 82 - 90 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] régression multiple
[Termes IGN] système de référence local
[Termes IGN] système de référence mondial
[Termes IGN] transformation de coordonnéesRésumé : (auteur) This paper provides an introduction to multiple regression equations as a method of performing geodetic datum transformations. The formulae are particularly useful when there are non-linear distortions that need to be built into the transformation model. However, the equations take the form of a one-way transformation, usually a local geodetic datum to a global datum. The standard procedure for applying the equations to obtain the reverse transformation only gives approximate results relative to the original model. This paper quantifies the problem and describes three methods for computing the reverse transformation (or inverse transformation) more accurately. Numéro de notice : A2018-178 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1080/00396265.2016.1244143 Date de publication en ligne : 31/10/2016 En ligne : https://doi.org/10.1080/00396265.2016.1244143 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89822
in Survey review > vol 50 n° 358 (January 2018) . - pp 82 - 90[article]The SMITSWAM method of datum transformations consisting of Standard Molodensky in two stages with applied misclosures / Andrew Carey Ruffhead in Survey review, vol 48 n° 350 (September 2016)
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Titre : The SMITSWAM method of datum transformations consisting of Standard Molodensky in two stages with applied misclosures Type de document : Article/Communication Auteurs : Andrew Carey Ruffhead, Auteur Année de publication : 2016 Article en page(s) : pp 376 - 384 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] approximation
[Termes IGN] ellipsoïde (géodésie)
[Termes IGN] transformation de coordonnéesRésumé : (auteur) For three-parameter datum transformations to be applied rigorously, geodetic coordinates on the first ellipsoid need to be converted to Cartesian coordinates before application of the shifts, then converted to geodetic coordinates on the second ellipsoid. The Standard Molodensky method of datum transformation is more direct but is inexact. It also fails to reproduce the original coordinates when applied forward and back. However, this paper shows a pattern of proportionality between the misclosures and the errors in the forward approximations. This gives rise to a new method of computing the transformations, best described as “Standard Molodensky in two stages with applied misclosures” (SMITSWAM). The method is shown to be more than 1600 times more accurate than Standard Molodensky, coming close to the accuracy of the rigorous approach. SMITSWAM is also shown to be around 48% faster than the traditional form of the rigorous method which uses iteration. Numéro de notice : A2016-643 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1080/00396265.2016.1191748 En ligne : https://doi.org/10.1080/00396265.2016.1191748 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81848
in Survey review > vol 48 n° 350 (September 2016) . - pp 376 - 384[article]