By: Philipp Gartner
Abstract
Geographical Information Systems are widely used tools for analysing, processing and visualizing of geodata. The new medium of the World Wide Web (WWW) provides a big platform to publish GIS maps to a large number of users. This new application characteristic can be called webGIS.
Since the amount of spatio-temporal data stored in databases and GIS increased enormously, webGIS applications become a promising tool to display these data to a broad audience. How these datasets are displayed technically depends on the applied visualization method. Besides others, OGC standards and W3C protocols exist.
Furthermore the visualization of spatio-temporal data is dependent on cartographical visualization techniques. These techniques define how the content of the data is visualised. The approach can be classified as either static or dynamic.
Towards a closer look to the visualization techniques the question arised, which temporal visualization method will present the spatio-temporal data best in order to fulfil certain user requirements? In order to answer this research question, a cooperation with two bird tracking information centres was established. The project used transmitter based location information from two bird species as data input. Stakeholders, either involved in the tracking project or researcher concerning migrational behaviour, discussed their visualization requirements by means of a created questionnaire. Two visualization methods and three cartographical visualization techniques were combined with stakeholder requirements in order to create different visualization modes.
Because of diverse presentation and exploration needs, the stakeholders were not eager to favour one specific visualization mode as most suitable. Nevertheless, both visualization methods have advantages and disadvantages. The OGC conform method is restricted to the static visualizations; while the W3C conform method is applicable to static as well as dynamic modes. The development of future webGIS applications goes towards interactive visualization explorations. That means, further research should not only focus on user visualization requirement but also on user demands concerning interactive tools for data exploration.