Technical Ramblings

A bit more than a year ago, when I was just learning how to use the Google Maps API, I put together a patch for the OpenGuides software, adding Google Maps support. It seemed the logical way to go: It wasn’t perfect, since Google Maps are obviously non-free, but it seemed like a better way to get the geographic output from OpenGuides out there than anything else at the time.

Since I did that, I’ve learned a lot. Remember that 18 months ago, I’d never installed MapServer, had no idea what PostGIS was, and didn’t realize that there were free alternatives to some of the things that Google had done. Also, 9 months ago, there was no OpenLayers, or any decent open alternative to the Google Maps API.

In the past 18 months, that’s all changed. I’ve done map cartography, I’ve done setting up of map servers, and I worked full time for several months on the OpenLayers project. Although my direction has changed slightly, I still work heavily with maps on a daily basis, and spend more of my time on things like TileCache, which lets you serve map tiles at hundreds of requests/second.

So, about a month ago, I went back to the Open Guide to Boston, and converted all the Google Maps API calls to OpenLayers API calls. The conversion took about an hour, as I replaced all the templates with the different code. (If I was writing it again, it would have taken less time, but this was my first large scale open source Javascript undertaking, long before I gained the knowledge I now have from working with OpenLayers.) In that hour, I was able to convert all the existing maps to use free data from MassGIS, rather than the copyrighted data from Google, and to have Google as a backup: a Map of Furniture Stores can show you the different. You’ll see that there are several layers — one of which is a roadmap provided by me, one from Google — and one from the USGS, topographic quad charts.

It’s possible that some of this could have been done using Google as the tool. There’s nothing really magical here. But now, the data in the guide is no longer displayed by default on top of closed source data that no one can have access to. Instead, it’s displayed on top of an open dataset provided by my state government.

This is how the world should work. The data that the government collects should be made available to the people for things exactly like this. It shouldn’t require a ‘grassroots remapping’: There are examples out there of how to do it right. I find it so depressing to talk to friends in the UK, who not only don’t have the 1:5000 scale quality road data that Massachusetts provides, but doesn’t even provide TIGER-level data that the geocoder on the Open Guide to Boston uses.

Free Guides, with Free Maps. That’s the way it should be. The fact that it isn’t everywhere is sad, but at least it’s good to know that the technology is there. Switching from Google to OpenLayers is an easy task — it’s what happens next that is a problem. You need the data from somewhere, and it’s unfortunate that that ‘somewhere’ needs to be Google for so many people. I’m thankful to MassGIS and to the US Government for providing the data I can use, and to all the people who helped me learn enough to realize that using Google for everything is heading the wrong way when you want to not be beholden to a specific set of restrictions placed on a corporate entity.

This entry was posted on Sunday, February 11th, 2007 at 8:46 am and is filed under Locality and Space, Mapserver, OpenGuides, OpenLayers, TileCache. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.