This past weekend I assisted in the organizing of an OpenStreetMap Mapping Party here in Cambridge. It was a diverse group of people, from all sorts of background, with various experience with mapping tools and GPS devices.
CC-SA 2.0 OSM
Why a mapping party in Cambridge, MA? One may say that the area is pretty well covered. Well, yes. Most of the data in Massachusetts was imported from MassGIS data. Why? MassGIS states that the data collection was funded by taxpayers, and therefore lies in the public domain.
This is a great start, but as we discovered throughout the day, that data was out of date, and in some cases, incorrect. Not like that was a surprise, though. Buildings are built, roads are relocated, and sidewalks are shifted. It’s just that it’s now up to us to keep it up to date.
In addition, we found out first-hand just how bad the ‘urban canyon’ effect is. Relying only on our GPS devices would have been disasterous, as the tracks bounce all over the place when you are walking between large buildings. It was impossible to map areas within these urban canyons relying on GPS reception alone. Fortunately, we were introduced to walking papers by Lars Ahlzen.
Walking Papers is a product of Stamen Design‘s Michal Migurski, and it’s a great low-tech solution for people who want to contribute to OpenStreetMap, but who don’t have a GPS, or don’t have the knack for gadgets (like many technophiles I know). These are paper maps for hand-annotating with pen or pencil. When you’re done, you can scan and upload your map back to walking papers for adding to OpenStreetMap (I’m almost there with my set in Cambridge, I’ll let you know how it goes).
Altogether, it was a fun afternoon, with warm beverages and snacks provided by Azavea. I hope we got some folks excited about OpenStreetMap, and how easy it is to improve our maps. Next time, instead of the city, I think I’ll map some trails in the woods around New England.
Update:
I printed my walking papers of the Kendall Square area, near our Cambridge office, and did some quick surveying on my way home last night. This morning, I tried scanning and uploading the image again. I found that the uploader was finicky, and it seemed to work when:
- File format is JPG (TIFF was a no-go)
- Scanned images were scanned as full-color photos, and not black & white photos or text
- Scanned image resolution was 300dpi
When I figured all that out, I was able to get my scanned print into walking-papers, and even added the walking-papers plugin into JOSM. I found that the tiles of my scanned print sometimes didn’t load in properly, but that may be due to operator error (impatience).
All in all, I think walking-papers is a really great addition to the OpenStreetMap ecosystem. Now you have one less reason to not be mapping your own town!
