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Developing the information infrastructure based on LADM – the case of Poland / K. J. Góźdź in Survey review, vol 48 n° 348 (May 2016)  

Public [article]  inSurvey review > vol 48 n° 348 (May 2016) . - pp 168 - 180 Titre : Developing the information infrastructure based on LADM – the case of Poland Type de document : Article/Communication Auteurs : K. J. Góźdź, Auteur ; Peter J. M. Van Oosterom, Auteur Année de publication : 2016 Article en page(s) : pp 168 - 180 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Infrastructure de données [Termes IGN] base de données foncières [Termes IGN] infrastructure nationale des données localisées [Termes IGN] norme [Termes IGN] Pologne [Termes IGN] utilisation du sol Résumé : (auteur) In this paper, the possibilities of developing the national information infrastructure by applying the Land Administration Domain Model (LADM) are discussed. Confirmation of the legitimacy of using the LADM within the (Spatial) Information Infrastructure (SII) context is illustrated with the case of Poland. Creating the information infrastructure is an immense challenge because its components are usually dispersed among various institutions responsible for their maintenance and dissemination. Co-existing spatial and non-spatial components of the information infrastructure require their proper integration. Moreover, the interdisciplinary nature of the SII results in combining objects from physical and legal world in one computer environment. The process of standardisation is the first step to refine land administration system and to make it more understandable and transparent for involved parties. The LADM, being officially adopted as an international standard ISO 19152, gives a basis for building national profiles and supports creating the European information infrastructure, enabling communication based on common terminology. This paper provides a brief overview of the current land information system in Poland emphasising the main issues in creating the national information infrastructure. Then, the general concept of the country profile for Poland with the adaptation of the LADM is described. With respect to the users’ expectations and requirements, the conceptual model is extended to information being outside the scope of LADM. As a final point, several technical aspects of implementing the complemented LADM country profile are explored. The results indicate that effective functioning of the information infrastructure requires proper integration of data, proceeded by analysing the contents of existing data sets, indicating key registers and defining a linkage system between them. Numéro de notice : A2016-269 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1179/1752270615Y.0000000018 En ligne : http://doi.org/10.1179/1752270615Y.0000000018 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=80820 [article]

Barycentre method for solving distance equations / X. Shuqiang in Survey review, vol 48 n° 348 (May 2016)  

Public [article]  inSurvey review > vol 48 n° 348 (May 2016) . - pp 188 - 194 Titre : Barycentre method for solving distance equations Type de document : Article/Communication Auteurs : X. Shuqiang, Auteur ; Y. Yuanxi, Auteur ; D. Yamin, Auteur Année de publication : 2016 Article en page(s) : pp 188 - 194 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Mathématique [Termes IGN] algorithme de Gauss-Newton [Termes IGN] barycentre [Termes IGN] distance [Termes IGN] équation [Termes IGN] itération [Termes IGN] méthode des moindres carrés Résumé : (auteur) When iteratively solving the distance equations, the Newton’s method has quadratic convergence but it requires the second-order derivatives. The Gauss–Newton’s method needs no information about the second-order derivatives but it may fail without the line search strategy. A simple method called barycentre method is proposed to locally solving the distance equations without the Hessian matrix, the matrix inversion and the line search strategy. The geometrical meaning of the non-linear least-squares solution of the distance equations is revealed that it is the barycentre of a particle system composed of the observational weights at the endpoints of observed distance vectors. By the geometrical meaning of the non-linear least squares, the authors structure an iterative equation to solve the distance equation, and then the convergence and the computational complexity of the method proposed is discussed. It shows that the barycentre method is a conservatively steepest decent method to guarantee the convergence and this method has good performances for solving well-conditioned problems. Ultimately, the method proposed is applied to well-condition and ill-posed positioning equations and the main results are verified. Numéro de notice : A2016-275 Affiliation des auteurs : non IGN Thématique : MATHEMATIQUE/POSITIONNEMENT Nature : Article DOI : 10.1179/1752270615Y.0000000020 En ligne : http://doi.org/10.1179/1752270615Y.0000000020 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=80824 [article]

Evaluating the use of GPS heights in water conservation applications / Ahmed F. Elaksher in Survey review, vol 48 n° 348 (May 2016)  

Public [article]  inSurvey review > vol 48 n° 348 (May 2016) . - pp 195 - 201 Titre : Evaluating the use of GPS heights in water conservation applications Type de document : Article/Communication Auteurs : Ahmed F. Elaksher, Auteur ; A. Fernald, Auteur ; F. Kapoko, Auteur Année de publication : 2016 Article en page(s) : pp 195 - 201 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Topographie [Termes IGN] altitude orthométrique [Termes IGN] analyse comparative [Termes IGN] GPS en mode statique [Termes IGN] hauteur ellipsoïdale [Termes IGN] niveau de l'eau [Termes IGN] nivellement indirect [Termes IGN] Nouveau-Mexique (Etats-Unis) [Termes IGN] positionnement par GPS [Termes IGN] positionnement statique rapide [Termes IGN] récepteur GPS [Termes IGN] station de contrôle [Termes IGN] station de référence Résumé : (auteur) Accurate water level elevations are imperative for water resource management. This paper presents the outcomes of a research study using GPS in measuring water level heights. The authors observed the water elevations of several wells, United States Geological Survey (USGS) gauges and acequia points at three different locations in North–Central New Mexico, USA. Different rapid static and static observation sessions were collected independently and adjusted using the nearby reference control stations. The authors used two different sets of receivers: four Topcon Hiper Lite+ and two Leica GPS1200 The authors were able to examine several network configurations with different continuously operating reference station (CORS) stations. Our findings were analogous to empirically expected errors and showed insignificant differences among the heights obtained from rapid static and static sessions at a 95% confidence level. The authors also compared the results with National Geodetic Survey online positioning users service (NGS OPUS) solutions and confirmed the accuracy of our measurements. As independent measurement technique, we measured the height differences among several of these points with conventional levelling surveys. Our GPS measurements provided small disagreements with height differences obtained with the terrestrial surveys, after the GPS heights were reduced to their orthometric correspondences. Based on these findings, current rapid static GPS positioning methodologies are capable of providing equivalent accuracies as those obtained by static GPS and ground surveying techniques. Numéro de notice : A2016-274 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1179/1752270615Y.0000000021 En ligne : http://doi.org/10.1179/1752270615Y.0000000021 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=80829 [article]

An effective toolkit for the interpolation and gross error detection of GPS time series / X. Wang in Survey review, vol 48 n° 348 (May 2016)  

Public [article]  inSurvey review > vol 48 n° 348 (May 2016) . - pp 202 - 211 Titre : An effective toolkit for the interpolation and gross error detection of GPS time series Type de document : Article/Communication Auteurs : X. Wang, Auteur ; Y. Cheng, Auteur ; S. Wu, Auteur ; K. Zhang, Auteur Année de publication : 2016 Article en page(s) : pp 202 - 211 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] analyse de spectre singulier [Termes IGN] coordonnées GPS [Termes IGN] détection d'erreur [Termes IGN] interpolation [Termes IGN] modèle de simulation [Termes IGN] série temporelle [Vedettes matières IGN] Traitement de données GNSS Résumé : (auteur) As data gaps and gross errors inevitably exist in GPS time series, robust detection and interpolation procedures are needed to obtain a uniform time series for various geospatial studies and applications. The use of traditional methods for this purpose is usually based on some improper assumptions, which are not derived based on the real properties of the data. Moreover, different interpolation methods may need to be investigated for interpolation for various gaps with different types and amount of missing data. These make the interpolation for missing data not easy. To address the issue of mentioned above, in this study, a data-analysis method named singular spectrum analysis (SSA) for missing data is assessed for reconstructing a reliable model from unevenly sampled time series without the need for any a priori knowledge of the time series data. In this method, the interpolation and detection of gross errors are carried out in one go along with the reliable reconstructed model. Both simulation data and real GPS data testing results showed that this was an efficient method for interpolation and gross error detection. Numéro de notice : A2016-276 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1179/1752270615Y.0000000023 En ligne : http://doi.org/10.1179/1752270615Y.0000000023 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=80830 [article]