METHODOLOGIES TO ENHANCE COMPLEX GEOMETRY ANALYSIS AND DISPLAY USING A DYNAMIC OBJECT-ORIENTED DBMS
The DESERT Action of European JRC (Joint Research Centre) is developing web tools to display maps and analyze meteorological data to improve understanding of drought and desertification, in Europe and the world.
For this purpose a system is designed and implemented using a PHP MapScript GIS engine. The system has to be able to produce classical maps showing relevant weather trends but also to understand the many other parameters influencing land degradation such as population pressure, elevation, soil properties and land management. Due to these manyfold needs to present geographical information the sofware developpers had to realise specific functions not being part of the core MapServer toolbox.
In our presentation we will explore these functions.
We will present dynamic legends, these are legends that change according to the geographic extent where the user is viewing, automated methods for relating polygon information of various scale/zoom levels, functions to quickly find a geometric feature, using optimized zoom to, Google Earth KML conversion and identify functions. Also functions to display trends in long periods using graphs based on the GD library will be presented.
The functions presented are based on a for purpose designed object oriented DB, in which the geographic features are stored in an object model, where legends and other repeated characteristics are organized to allowing the software engineers to develop generic functions for displaying and analysing content in a specific table. Finally the engineers also choose to store components of the system itself in the database, thus enhancing software version control from quick content change. We can significantly change the look and feel of the system without deploying (and testing) new software.
Information will be displayed depending or rules whilst analysing what we call operational metadata, such as primary and foreing key constraints.
Diego Magni - Arcadia Sistemi Informativi Territoriali s.r.l.
Alfred De Jager - EC JRC