Timesliding canvas maplayer
After someone saw my BAG building data movie 
he asked if it would be possible to create an interactive map of the entire Netherlands. This made me think, since creating the movie was a very time consuming action. The problem is that there are about 6 million buildings in the BAG database. This makes the data a bit unwieldy to use directly in the browser. The old fashioned way to do time series on maps involves creating a new layer for each time-moment (year in this case). This would mean that there would be over 150 layers to be loaded on the map and switching between those for the ‘time sliding’ effect. Apart from the hideous task to set up 150 almost the same layers, it would end up with too much images for a browser to handle.
Perceived WCS inaccuracy
Working with WCS I discovered a small but noticable shift of data in all three major OSS WCS applications:
- Geoserver 2.0 (SNAPSHOT downloaded 8 december 10.19UTC)
- Mapserver 5.6.0 (MS4W Base installer v3.0 Beta 7 + MapServer 5.6.0 release Upgrade)
- Deegree 2.3rc1 (Apache Tomcat 5.5.28)
To find out what the problem exactly was I’ve done some testing. I’ve taken a GeoTiff and configured all three the WCS applications to serve it. Gdalinfo gives us the following information, basically it is a GeoTIFF in epsg:3035 with a native resolution of 100m/pixel.
WFS 1.1.0, GML 3.1.1 and OpenLayers
In the INSPIRE framework we are working on the ESDIN project and are using the EuroGeoNames (EGN) project as an implementation of ESDIN. INSPIRE is a big thing within the GIS world in Europe and loads of documents have been written so far.
We’re involved in both ESDIN and EGN and we decided to use the latter as a trial for the first. Together with our partners we’ve setup a series of servers to fulfill the needs of the projects. The main standard used is the latest WFS and GML versions, which have the annoying disadvantage that there are few clients available.