What are some current examples of web services serving thematic mapping based on free and open source software? The thematic mapping could be in the form of choropleth or point layers. It would be very interesting to see some good publicly accessible geo-information systems, with the emphasis as much on simple but well-implemented projects as on those that are technically accomplished.
[GIS] Examples of thematic mapping web services built with FOSS GIS
open-source-gisweb serviceweb-mapping
Related Solutions
EDIT: (Jan 13) I'm still seeking information on exactly how best to store a 3 dimensional 16-bit integer BIP raster and be able to efficiently query a single z-axis "column" of data. I don't want to convert it to a 32-bit format (because that would double its file size from its current 16-bit form).
Querying such a raster should not really pose large problems. You can read binary data directly using all program languages, and access is fast. Just make sure that you store your data in a file format which has all metadata in a seperate file. BIP is such a format
eg in php, assuming that the file is row major order (otherwise switch x and y), with $x and $y the position in your grid(counting from 0), $nx, $ny and $nz the number of pixels in each dimension and $nb the number of bytes per gridcell:
$fp = fopen('yourfile.bil', 'r');
fseek ($fp, $nz*$nb*($y*$nx +$x))//this is a very fast operation
// read some data
$data = fread($fp, $nz*nb);//this is also very fast
Just make sure that you access the right pixel: does counting start from top left or not, ...
Some extra info: After reading the data, you should convert it to floats. E.g.:
$dataf=unpack("f*", $data);
print_r($dataf);
In case your host does not support uploading large files, you could eg split up your bip file in eg 8 bip files.
Some more info on how I would do the rest of the website: since your data is static, you could generate a small mapviewer using gdal2tiles and openlayers. http://www.gdal.org/gdal2tiles.html In fact, since you say that "I don't really need scalability--this project is mostly to enable a few peer researchers to have easier access to my data than sending an 8GB file and loading it in ENVI."you could maybe even do without using a webgis toolbox: just let your users click on the image and catch the coordinates: http://www.emanueleferonato.com/2006/09/02/click-image-and-get-coordinates-with-javascript/
(though you should find a way to present your 5000x5000 image nicely)
Best Answer
There is a nice project from SEAI mapping wind and geothermal energy potential. Very neat example of using MapFish and OpenLayers.
Although not purely about maapping I like design of EveryBlock. As far as I know it is based on GeoDjango, OpenLayers and Mapnik. And it's open source.