ToToPI (Topographie de Tours Pré-Industriel), a GIS for understanding urban dynamics based on the OH_FET model (Social Use, Space and Time)

http://proceedings.caaconference.org/files/2009/41_Rodier_et_al_CAA2009.pdfInternational audienceToToPI, for Topography of Tours Pre-Industrial, is a GIS for studying of the city of Tours (France) in large time span. The concepts for understanding the urban dynamic is based on considering the town as a set of complex objects, taking a systemic approach. The town system used to study the urban fabric over large time spans is composed of three sub-systems relating to historical objects from the level of the excavation to that of the former urban space: function (social use), space (location, surface area and morphology) and time (dating, duration and chronology). The historical object is the analytical unit of the studied space. It is the Cartesian product of the three sets, Social use, Space and Time, from which it stems. The OH_FET model is based on this process. The Historical Object (OH) is broken down into three types of simple object, functional (EF), spatial (ES) and temporal (ET). The relationships between these three sets each characterize an interaction (social use-space, social use-time, time-space, or function-space-time). In addition to reconstructing the OH, they allow urban changes to be observed by analyzing the distributions and mapping of each of the entities singly or two-by-two. The originality of this procedure lies in its approach whereby it is possible to start not from the mapping of a phenomenon at a time t1 and comparing it to that at a time t2, but to look at it in the same way whether its input is social use, space or time. The heuristic value of this modelling lies in the shift from description (what, where, when) to understanding the phenomena of change (how, why). The Implementation of OH_FET model in ToToPI, with classical GIS software (ArcGIS from ESRI), makes possible on one hand the analysis of data sets in large time span and on the other hand the creation of new analyses (and of new products which result from it as the temporal mappings). The paper will explain how GIS is used for historical data processing to understand time-space dynamics

How to quickly detect the overlap and the consistency between LADM with LandInfra and LandXML : application of schema matching techniques.

In this paper, we explore the schema matching techniques to compare the content of three geospatial standards which are LADM, LandInfra (InfraGML) and LandXML. Those standards all refer to the concept of “land” and we will try to quantify the similarity of them based on syntax and semantic comparison of the class names exposed in their respective schema. Consequently, we will demonstrate the applicability, the accuracy and the usefulness (rapidity and automation) of schema matching techniques for comparing the content of standards. The comparison is performed with XSD (XML Schema Definition) files that describe the schema in English. The results show that syntactic match rate between LADM-LandInfra (54%) is higher than LADM-LandXML (10%). In adding the semantic information extracted from Wordnet, the match rate between LADM-LandInfra goes to 84% and 59% for LADMLandXML. In comparing our matching results with two independent sources of information that already and manually compared these three standards, we obtained distinctive results. The correctness of LADM-LandInfra is 60%, while the correctness of LADM-LandXML is only 20%. The applicability of schema matching is positively demonstrated while the usefulness and the accuracy still need further improvements in order to make any statement.Dans ce papier, nous explorons les techniques d’appariement de schémas pour comparer le contenu de trois standards géospatiaux soit LADM, LandInfra (InfraGML) and LandXML. Ces trois standards réfèrent au concept de « land » et nous allons tenter de quantifier leur similitude en tenant compte de la syntaxe et de la sémantique des noms de classe contenu dans leur schéma respectif. Nous allons ainsi démontrer l’applicabilité, l’exactitude et la facilité (rapidité et automation) des techniques d’appariement de schémas. La comparaison est effectuée à partir des fichiers XSD (XML Schema Definition), qui présentent la modélisation en anglais des standards. Les résultats montrent que, lorsqu’uniquement la syntaxe est prise en compte, le taux d’appariement de LADM-LandInfra (54%) est plus élevé que celui de LADM-LandXML (10%). En tenant compte des relations sémantiques possibles extraites de Wordnet, le taux d’appariement de LADM-LandInfra grimpe à 84%, alors qu’il revient à 59% pour LADMLandXML. En comparant nos résultats avec des sources d’information externes qui ont déjà comparées manuellement ces trois standards, nous obtenons un taux d’exactitude de 60% pour LADM-LandInfra et de 20% pour LADM-LandXML. L’applicabilité des techniques d’appariement de schémas est démontrée par nos expérimentations tandis que l’exactitude et la facilité montrent des résultats divergeant qui nécessiteront d’autres tests et analyses

How to Enrich the Semantics of Geospatial Databases by Properly Expressing 3D Objects in a Conceptual Model

Abstract. Geospatial conceptual data models represent semantic information about the real world that will be implemented in a spatial database. When linked to a repository, they offer a rich basis for formal ontologies. Several spatial extension

Approche intégrée de traitements numériques des données bathymétriques acoustiques et optiques en vue de réduire l'intervention humaine

Québec Université Laval, Bibliothèque 201

3D Cadastre: With or Without Subsurface Utility Network?

Within the global trend of designing and implementing 3D cadastre, this paper offers a discussion about the integration of subsurface utility networks in such land tenure systems. Three questions are addressed: Do we need to register underground objects? Should underground networks be registered in the Land Register, with the same specifications as land parcels? Which information should be part of the registration process? The case study of the Quebec jurisdiction is used to illustrate some aspects of the discussion. This paper attempts to help land administration authorities and stakeholders better assess the suitability of full 3D Cadastre

Terrestrial LiDAR Capabilities for 3D Data Acquisition (Indoor and Outdoor) in the Context of Cadastral Modelling: A Comparative Analysis for Apartment Units

The paper presents a comparison of terrestrial LiDAR and Distancemeter for surveying 3D spatial data of property units (indoor and outdoor) and producing cadastral representations (2D and 3D). Two study sites representing apartment buildings (co-ownership units) were surveyed with both instruments and six criteria related to data acquisition steps (survey time, number of measures, number of operators) and data modeling steps (preprocessing time, time for modelling the geometry of the objects, completeness) are used to enable the comparison. To produce 2D maps LiDAR technology ended with performance in term of survey and modeling time a little lower compare to Distancemeter. To produce 3D models LiDAR technology shows better results compare to Distancemeter. The number of objects to model and the geometric complexity of these objects are important criteria to take into consideration to determine the advantages of LiDAR technology compared to traditional instruments. For instance, LiDAR point cloud offers the possibility of producing more detailed 3D model (i.e. containing not only cadastral limits)

Visualization, Distribution and Delivery of 3D Parcels: Position Paper 4

This paper is the second of two position papers that serve as the basis for discussion in a forum held at the 4th International on 3D Cadastres, 9-11 November 2014, Dubai, UAE. The first paper was published in 2011 (Pouliot, 2011). The overall objective of the FIG Working Group discussion is to provide feedback to the FIG Commission 3 (Spatial Information Management) and FIG Commission 7 (Cadastre and Land Management) and EuroSDR. Four working sessions are planned; this paper applies to working session #4