Technical background

Technical background of the modules

„Europe – side by side“ (coming up soon) and „Europe -construction and perception“ are flash-applications, programmed in the Flash-API using ActionScript2. The contours of the countries derive from the Natural Earth 1:50Mio dataset, applying the ETRS898 Lambert Azimuthal Equal Area Coordinate Reference System. To avoid distortion and to keep the north orientation of the state, the longitude zones were adjusted.
The module „Europe – abstract spatial time travel“ is an interactive flash-timeline-animation with  ActionScript 3 Elements. The circle cartograms are instanced on the fly using a database consisting of a coordinate dataset derived from a slightly modified algorithm  for „Dorling Cartograms“ focused on keeping common borders, if possible sometimes disregarding centroids, based on a spatial dataset composed  using the historical GIS of the Leibniz Institute of European History. The second dataset on the historical sizes of European countries has been compiled from various sources, mainly statistical almanacs.
The „build your own Europe“ module was developed using OMOA, an open source cartographic visualisation framework made available by the IFL. OMOA is written in ActionScript 3 and implements an object oriented software model of a cartographic sign system for the Flash platform, complete with a cartographic data model that incorporates geometric data as well as multidimensional statistical data. The role of the OMOA framework is to handle, for example, general tasks such as providing layers with geometric data, to manage the rendering of map symbols and to handle the styling of symbol attributes according to statistical data.
The „Europe in Bubbles“ module was visualised using the Protovis Java-Script Framework, designed by the Stanford Visualization Group to make interactive data-visualisation more accessible. Thus, Protovis takes a graphical approach to data visualisation by allowing the web designer to specify how the data should be encoded in the marks representing it on the screen. Protovis uses SVG image for rendering, allowing visualisations to be inserted into html-pages. However, the SVG-interpreter must be installed to parse and process SVG.