All the trees as (sort of) Open Data

Remember the Charlottetown Tree Inventory? Well the City of Charlottetown announced today that it has released a web app exposing most of the data in the inventory, with a map interface.

It’s not quite open data in the classic sense of the term, but it’s a step closer. Under the hood is a WMS service, which you can think of as a way for web maps — their map, your map, my map — to request data about the trees of Charlottetown. So I can craft a request to, say, grab an image of the trees in Hillsborough Square that looks like this:,5818253.7900264,-7026189.6355301,5818496.8358898&WIDTH=1653&HEIGHT=407

Which returns this image:

The trees of Hillsborough Square in Charlottetown, returned as an image from the city's WMS server.

The WMS server, however, doesn’t appear to support returning anything other than images, as setting the FORMAT parameter to XML or JSON returns an error. So the WMS server is more like a picture of open data than open data itself.

But, like I said, it’s a step.