Eveline Bernier

A Data Warehouse Strategy for on-Demand Multiscale Mapping

Publisher Summary With the advent of web mapping applications, todays users of geographic information are more aware of their requirements and are now for customized products specifically suited to their needs. These applications must, among other things, be able to present the same phenomenon at different levels of abstraction and according to different points of view. As with any web application, they must also provide fast response times. Automatic generalization mechanisms should form part of these applications. Given that such applications are web-based, response times must be very fast and generalization must take place on-the-fly. Unfortunately, there is no complete solution to automatic generalization. Although some operators require little control, complex ones still require human intervention. As an alternative, multiple representation databases have been proposed. This chapter presents an innovative strategy for multiscale on-demand mapping. This strategy is akin to data warehousing architecture where automatic cartographic generalization (CG) and multiple representations (MR) are distributed between the MR-centric warehouse and specialized CG-centric data marts. It also explains the underlying philosophy and the data warehousing architecture. The experiment in building a multiple representation data warehouse from eight data sources in the context of the GEMURE (Generalization and Multiple Representations for on-demand map production and delivery) project is also discussed. Finally, this chapter introduces UMapIT (Unrestricted MAPping Interactive Tool), a web-based on-demand mapping tool offering flexible seamless generalization.

Web services-oriented architectures for mobile SOLAP applications

With the growing popularity of mobile computing and the empowerment of mobile devices by high end-users and decision-makers, the development of architectures based on web services for the deployment of mobile Spatial OLAP (SOLAP) applications is being perceived as a powerful solution. This paper deals with geospatial (web) Services-Oriented Architectures (SOA) for mobile processing of geo-decisional information. The paper first reviews the underlying concepts of typical SOLAP applications as well as the general concepts of mobile computing. The existing SOLAP functionalities are presented and their viability/usefulness in a mobile environment are discussed. Different web services based on an extended geospatial SOA are then proposed in order to tackle the several issues related to mobile SOLAP. Finally, several research challenges and outlooks are discussed.

Toward Self-Generalizing Objects and On-the-Fly Map Generalization

Map generalization is a complex task that sometimes requires human intervention. In order to support such a process on the fly, we propose a generalization approach based on self-generalizing objects (SGOs) that encapsulate geometric patterns (forms common to several cartographic features), generalization algorithms, and spatial integrity constraints. During a database enrichment process, an SGO is created and associated with a cartographic feature or a group of features. Each SGO created is then transformed into a software agent (SGO agent) in a multi-agent on-the-fly map-generalization system. SGO agents are equipped with behaviours that enable them to coordinate the generalization process. This article presents the concept of the SGO and two prototypes developed to support this approach: a prototype for the creation of SGOs and another for the on-the-fly map generalization (which uses the created SGOs).

UMapIT© (Unrestricted Mapping Interactive Tool): Merging the datacube paradigm with an occurrence-based approach to support on-demand web mapping

UMapIT is an on-demand web mapping tool that is being developed in an attempt to provide Internet users with flexible means to personalize maps and interactively navigate within them. Based on a specific multiple representation database structure, it offers new functionalities to be applied at the occurrence level. These innovative functionalities come from the datacube paradigm. They include geometric drills which allow the user to navigate between the different LoDs (Level of Detail) associated with an object or to the different geometries of a same LoD that are aimed at different purposes. These functionalities also address the semantic and graphic aspects as well, offering further flexibility to the users interested in navigating among the different meanings associated with an object or to change its visual variables (e.g., color, symbol) without affecting other occurrences of the same class. Furthermore, the underlying structure of UMapIT allows for the support of “GenZoom” operations that adjust each object’s geometry individually according to the map scale, simulating on-the-fly cartographic generalization. The objective of this chapter is to illustrate the new capabilities offered by merging the datacube paradigm with an occurrence-based approach for on-demand web mapping. Emphasis is given to fundamental concepts and to their implementation into UMapIT. Such merging of GIS and datacube concepts, which emerged from the Business Intelligence (BI) field, has raised a lot of interest and research funding in Canada, reflecting the evolution going on in this country from spatial data management (using transactional systems) towards highly flexible spatial analytical systems (using geospatial intelligence technologies). This chapter also provides a solution to the desire of Canadian organisations to offer better map-on-demand web services.

Cartographie sur demande sur le web et bases de données multidimensionnelles. De la personnalisation par couches cartographiques à la personnalisation par occurrences

Recent years have witnessed the emerging of web mapping applications. These applications allow a user to have access to spatial data, to support a descriptive query or map visualization and production. However, existing applications are rather limited regarding the flexibility offered to the user. This paper proposes to revisit and enrich the Map-on-Demand concept. We present the limitations of existing applications and suggest a new database structure allowing the development of more flexible on-demand web mapping applications. Based on the VUEL concept, this structure supports three types of multiplicities at the class level as well as at the occurrence level: geometric, semantic, graphic. In order to test and demonstrate all the flexibility of such a structure, we present an on-demand web mapping application currently under development. MOTS-CLÉS: cartographie sur demande, représentations multiples, VUEL, cartographie sur le web, base de données spatiales, base de données multidimensionnelle.