Mapping Open Streets
Mapping is fun. Picking out the way things should look, when information should be displayed, what info should be on a map — it’s pretty nifty. Looking at the various resolutions of data, making rendering decisions based on time and quality of data needed at that level… it’s nifty.
Schuyler and I have been working with the Openstreetmap data, trying to figure out how to make a fast WMS server available. Seems like we’re getting pretty close now: generating various levels of polyline simplification ranging in degree, giving a set of 5 layers to be used at scales ranging from above 3 million all the way down to 20,000 without significant loss of data, then displaying the full quality data below that.
GRASS is being used to create the polylines and clean the data, and I’m using qgis to view the different layers. qgis, btw, is a great little GIS program for testing out various layer files you might find on the intarweb. It’s a bit slow for huge (dozens of thousands) numbers of polylines, but for most purposes, it’s great, has nice zooming features, and lets you check out some of the fields that are stored in a file without having to resort to things like ogrinfo.
All in all, I like this mapping stuff. Now, I need to figure out how to make money doing this.