Friday 13 June 2008

From Data to Knowledge using Google Maps?

About time for another post I think. This time about things I'm doing with data which I turn into useable information in the hope that it can generate new knowledge. Well, that's the basic idea. Specifically, I've been playing around with google mashup editor, kml and kmz files, and Index of Multiple Deprivation data for 2007. What I've been trying to do is work my way round methods to display IMD data on google maps so that anyone can view it, understand it and maybe even remember it.

One of the main problems with using IMD data is that it means using lots of polygons and when you try to load them in google maps they render very slowly and sometime you get a script error in your browser (IE and FF). This is something to do with the way it all works 'under the hood' but I've been trying to investigate ways to make rendering polygons quicker... We'll see. Here's an example I created quickly with google mashup editor for an area in North Liverpool:

http://jrf-googlemaps-test.googlemashups.com/ - see how polygons load slowly


I've been reading and listening and watching online and it seems once you get beyond about 100 polygons everything goes awry. The solution would appear to be image/tile overlays but then this has some limitations that go against what I'm trying to achieve (query clickability, for example). I know people at CASA have used similar approach with their Gmap creator (I've used this and it works very well) and I can understand why but I just wonder if there is another way...


Since I'm on the subject of CASA, everyone with an interest in GIS/spatial analysis should go and see MapTube. This is really part of a much wider project about spatial literacy - which I am all for! I've said enough today. Will try a less technical post next time.