Geospatial data integration and visualisation using open standard Gilles TALADOIRE

1. Geospatial data integration and visualisation using open standard Gilles TALADOIRE University of New Caledonia (UNC) TIARE Computer Science Laboratory New Caledonia a project with IRD The French scientific research institutefor development LATICAL Remote Sensing Laboratory New Caledonia

2. Where is New Caledonia ?

3. Connected systems : expert systems, neural networks, multi-agents systems, data mining systems, image processing and analysis, simulations, scientific model, … ==> heterogeneous systems ==> heterogeneous formats Data visualisation adapted to the different users of an environmental project available on Internet, graphically satellite sensor, aerial sensor, ground sensor ==> heterogeneous data (textual, numerical, vector, images, …) ==> heterogeneous formats conceptual modelling, storage and extraction ==> heterogeneous systems (GIS, DBMS, …) ==> heterogeneous formats Environmental Information System System integration : From acquisition to visualisation Data AcquisitionRemote Sensing Ground Sensor Data Archiving : Conception Storage Extraction Data Processing and Analysis User Interface

4. Independent systems (generally) ==> incompatibility or incoherence in this process • Many partners involved in environmental projects • (expert firm, administration, research institute, …) • ==> Not the same methods • Not the same software • Not a single place ==> Heterogeneous Data, Formats and Systems ==> The generalised use of standards

5. Existing standardisation initiatives In the domain of the internet : World Wide Web Consortium (W3C) Extensible Markup Language (XML) (the universal format for structured documents and data on the Web) Scalable Vector Graphics (SVG) (An application of XML for describing two-dimensional graphics) In the domain of geospatial information : the Technical Comity ISO 211 : the standardisation in the field of digital geographic information the OpenGIS consortium the definition of specification to define transparent access to heterogeneous geodata and geoprocessing resources in a networked environment Geographic Markup Language (GML)

6. Architecture for system integration System integration : From acquisition to visualisation Data Acquisition : Remote Sensing Ground Sensor Data Archiving : Conception Storage Extraction Data Processing and Analysis User Interface GML GML GML SVG ==> The use of GML as common data interface ==> The use of SVG as visualisation solution

7. Creation of Import/Export module

8. Visualisation : from GML to SVG

9. Correspondence between objects Geometric objet Correspondence

10. Feature Correspondence The use of the 'class' property of graphical objects to identify the element origin The properties of one feature are grouped with the <g> element The features collections are to group with the <g> element The non-geometric properties could be visualised as text on the map like a legend of the object

11. Example : A water tank has a name and a Point location

12. Display style • No style in GML 2.0 • In SVG, three common usage for styling : • directly in the SVG content • SVG content generated as the output from XSLT transformation • SVG content styled with CSS ==> Styling with CSS style sheet using the class names given to SVGelements : flexible to change the map presentation easy to do

13. Example style sheet "watertank.css" .WaterTank {display:inline} .WaterTanklocation {fill:red;stroke:blue;stroke-width:2; visibility:visible} .WaterTankname {fill:black; visibility:visible} part of SVG file SVG rendering <g class="WaterTank" id="Drueulu1"> <rect y="357" x="507" height="10" width="10" class="WaterTanklocation"/> <text y="362.0" x="512.0" class="WaterTankname">Drueulu1</text> </g>

14. Fusion The generic SVG generator : - a transformation XSL : XSLT designed specially or - a program that parse the XML file : for special processing XLST transformations generic at two levels : - the application uses only geometric properties defined in the GML features schema, a general XSLT style sheet can be defined and used for all applications of this kind. - the GML application schema use specific geometric properties, the defined XSLT style sheet can be only use with the applications using this schema.

15. Extensions Functionality to add in a generic way : The interactivity to manage layers, for zoom and moving functions The automatic generation of legends The use of links and associations of GML - to visualise the links between the features to show dependencies Example : a water tank supply water to a village, a line is drawn from the tank to the village. - to establish hyperlink between graphical elements The GML schema parsing : - to develop a style sheet editor which propose features and properties of the schema - to realise a automatic style sheet generator from the schema The management of temporal series to animate objects on the map

16. Conclusion First step Spatial data visualisation with a correspondence between descriptive data and graphical data Global project to integrate systems with general use of GML as standard format

17. Thanks to : I3S laboratory (University of Nice-Sophia Antipolis - CNRS)to invited me from september 2000 to june 2001