1,720,975 research outputs found
“Web-GIS” e “web-mapping”:Aspetti tecnici per una cartografia partecipata.
No full textGeographical Information Systems (GIS) are environments for acquiring, processing and sharing geospatial-data. Today, the main access to map information is through the Internet and in this way map information become more easily accessible and available to users. The advent of web mapping can be considered as the major new trend in cartography. Previously, cartography was restricted to a few companies, institutes and mapping agencies, requiring expensive and complex hard- and software as well as skilled cartographers and geomatics engineers. The cheap and easy transfer of geo-data across the internet allows the integration of distributed data sources, opening opportunities. Everyone with minimal know-how and infrastructure can become a geo-data provider. This can be both an advantage and a disadvantage: while it allows everyone to produce maps and considerably enlarges the audience but it also increases errors and lack in the available map information due to the insufficient knowledge of cartographic and geographic principles and may introduce flaws during the preparation, analysis and presentation of geographic and cartographic data. While “web mapper” primarily deals with technological issues, the cartographer additionally studies theoretic aspects: the use of web maps, the evaluation and optimization of techniques and workflows, the usability of web maps, social aspects, and more. Because of this he plays a key role and has multiple functions, such as supervisor on the geographic analysis and cartographic methods and principles.
The purpose of this paper is to provide information on the new opportunities and challenges offered by the web technologies for cartography and related geosciences. It describes the developments, changes and prospects of the mapping discipline in the framework of the web development, in fact as the number of geospatial services increased rapidly, an immediate need of rigorous methodologies of data mining and of quality assessment is grown up.
In particular the web-GIS applications allow the geo-data distribution in internet and intranet exploiting the spatial analysis and maps performed in desktop GIS software.
We can summarize the Web-GIS workflow following these three steps: i) user sends (trough a dedicated web interface) a request in which is defined the area of interest and the data required, ii) based on the received request the Web-GIS engine search in his archive the information (file, image, ODBC, OGC Web-Service) and returns the specified part of territory, iii) one or more images are generated and sent to user-client.
Four are the main technological components of the system: the Geo-Data, the web-server, the map server and a client interface.
A new interesting new development in Geo-Information is the Collaborative maps where various people collaborate to create and improve maps on the Web. This systems may have a great potential however many technical (simultaneous editing across the web of geographic features) and methodological problems may occur; the possibility to allow to a huge number of user to manipulate data can’t require a minimal quality check, before data goes public. This involves different aspect in order to improve the quality of geographic information on the web
scanner analysis and morfological transformation of environmental anthropized sites: the case study of Governolo’s ancient dams
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Local and global approaches for the integration of up-to-date geo-db and ancient maps within the Atl@s portal
No full textIn the framework of the Atl@s portal project, aimed to achieve the georeferencing of historical cartography into modern mapping grids, in this paper a task concerning the integration of up-to-date spatial geo-db to ancient maps is presented. The main aim is to guarantee the web visualization and diffusion of the geo-iconographic historical contents in a detailed territorial dimension. The research is focused on algorithms and tools implemented within open source environment to support advanced georeferencing methodologies, to define and test technical specifications, and to improve an automatic approach. The standard procedure for georeferencing historical maps is based on the use of ground control points to compute an independent transformation for each map sheet (“local” approach). Here a “global” solution, which also includes some adjacency constraints between close sheets, is proposed. Furthermore, some initial tests are described by considering the “Map of the Astronomi di Brera” of Milano city (Italy, 1807), made up of 39 sheets at 1:1,000 scale
Navigating on the past, as a bird flight, at the territorial scale of historical topographic maps. WMS on the “Corografie delle Province del Regno Lombardo-Veneto”, for accessing cadastral map catalogue
No full textThe research presented here has developed within the project "Atl@s of historical cadastral and topographic maps of Lombardy (2009-2011)" funded by 'Fondazione Cariplo', involving 'Politecnico di Milano - BEST Dept.' (project leader), 'Archivio di Stato di Milano', 'Agenzia del Territorio', 'Centro Studi PIM', 'Regione Lombardia', 'Comune di Gorgonzola' (partners). The first release of the geo-portal (www.atlantestoricolombardia.it), has been presented to the public on 19th January 2010 after a year's work. Conceived in the form of a modern Atl@s, it has been designed with a double level access to the historical cadastral series available by ASMi ('Catasto Teresiano', 'Lombardo Veneto', 'Cessato Catasto'), together with samples of 'Impianto in conservazione' by AdT (Italian Cadastral Administration): besides a catalogue approach level based on classical research keys (the application, Divenire©, has been inherited by ASMi from the Archive of Venice), an open geographic level has been implemented by the research group of Politecnico, with ongoing functionalities, based on a territorial regional basis, obtained experimenting and georeferencing small scale topographic maps, principally here focused on the historical chorographic maps. The methodologies, the reliability and feasibility of the georeferenced output, and the overall potentiality to use them as a gate to access the local scale represented by the spread diffusion of the cadastral series, are the topics discussed. Due to the high number of historical cadastral sheets, the generation of a systematic GeoDB on the local cadastral series - with a rigorous georeferencing method, already documented within the research - shall be faced by government policies and by algorithm automation, to become sustainable in the next years, in terms of time and costs. Thus, in the meantime, few functionalities are being tested to allow an agile user access, based on a geographic approach to the non georeferenced sheets, straightening the immediate content of the geographic language to a large public demand, respect to the simple key queries, through Web Mapping Services (WMS) developed on the small scale map: ASMi is going to share - over this project through the portal - more than 28.000 sheet units, that can find a challenge in the geographic fruition. Flying the territory of the past with the small scale synthesis, its political assets and physical elements, such as the hydrographic network, can offer interesting thematic cultural opportunities to knowledge dissemination of 'our territory' and its preservation
Local and global approaches for the integration of up-to-date geo-db and ancient maps within the Atl@s portal
No full textIn the framework of the Atl@s portal project, aimed to achieve the georeferencing of historical cartography into modern mapping grids, in this paper a task concerning the integration of up-to-date spatial geo-db to ancient maps is presented. The main aim is to guarantee the web visualization and diffusion of the geo-iconographic historical contents in a detailed territorial dimension. The research is focused on algorithms and tools implemented within open source environment to support advanced georeferencing methodologies, to define and test technical specifications, and to improve an automatic approach. The standard procedure for georeferencing historical maps is based on the use of ground control points to compute an independent transformation for each map sheet (“local” approach). Here a “global” solution, which also includes some adjacency constraints between close sheets, is proposed. Furthermore, some initial tests are described by considering the “Map of the Astronomi di Brera” of Milano city (Italy, 1807), made up of 39 sheets at 1:1,000 scal
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