Armed with some printouts from fieldpapers.org, this intrepid neophyte cartographer went out into the SFSU campus field for some ground-truthing and OSM verification.

First stop was the eastern side o campus where fellow #SFSUCarto member KingPenguin had done the building footprints for The Towers and other nearby residence halls, a part of campus I had never set foot in and now refer to as The Sunset as it’s location at SFSU is akin to the Sunset neighborhood of larger San Francisco (kinda North by Northwest)

Right off the bat, I took a footpath not represented by the OSM map of the area, so noted that, then added some official names and addresses for the buildings. Recycling bins are quite prevalent here and so I made a note of that as well. I was wishing I had a satellite image as well as what existed on the OSM map, I really think you need both to make quality edits. ([changeset] (osm.org/changeset/21088035))

Next stop I had a satellite image for… the OSM map just had “Cox Stadium” as a monolithic polygon covering this whole zone, but I knew there was a running track and other features. On arrival, it is much more a field than a stadium and don’t even get me started on the whole corporate takeover of naming stadiums and the like. I traced out the component parts of this area (bleachers, pressbox, track and field) among the tall cypress trees that surround the field. ([changeset] (osm.org/changeset/21088035))

Up to now, I have had limited experience mapping in the field…dropping a few GPS crumbs here and there amid the Farallon Islands, and this was a very good experience, using satellite images, campus maps and the existing OSM points, lines and areas to ground-truth a new lil piece of my local geography.

… See full entry

Right along the bush in Bangassou, added 30-odd small buildings in the southeast part of this troubled city in the Central African Republic…kind of connects the dots from that world to this a continent away. Check the changeset for the details.

Humanitarian and OSM seem to fit together like PB&J, so I’m glad and grateful to be contributing in some small digitizing way… I often think of mapping as a political act, especially when it involves indigenous people, whether in Africa or the American southwest.

I was struck by how small the building footprints are in Bangassou, and out in the wildlife boundary how vulnerable a native population would be in the face of war and ethnic strife.

I must say the SFSU campus already looks more filled in the day after our lil mini-Hackathon for #SFCarto, even though I can’t remember anyone calling it that…very cool,

Onto Phase Two, ground truth verification with field papers in hand…I wonder if there’s an ArcPad app possibility here, which would crank up the open-source level of the geospatial revolution…

Finally got my feet wet contributing to OSM, and with the cutting-edge in-browser iD editor (thanx MapBox!), it was really a snap to digitize some building footprints around the northeast corner of SFSU campus.

This was my first active experience with Open Street Map, though I have been aware of their work for some time, including the (way back) lack of traction in the US perhaps due to the USGS already mapping it for free. But a confluence of events now sees the OSM movement picking up steam stateside and I’m glad to be finally contributing.

My initial contribution (tracked by changeset #210555275 ) was: Added SFSU Greenhouse2, University Park North Rental Office Building, Thornton Hall Annex Buildings N,O,P,Q,R,S, and improved building footprint of Thornton Hall on SFSU campus for #SFSUCarto.

The only difficulties I encounted were around the zoom levels maxing out at 19 for map view and some waiting times for the map tiles to render. Also, while the browser-based iD editor is a revelation, the dark background is not the best for accurate digitizing. Finally, the unavoidable shadows and trees from the Bing satellite imagery made it a bit challenging to trace all the building outlines, but with patience and guesstimation, the areas got closed.

I digg the instant gratification of online real-time digitizing, especially compared to my other stints fighting with the ArcGIS editor tools on a complex geologic map of the Modoc region of California, work I did as a consultant with the California Geologic Survey.

Overall, I found a blank space on the map and was able to start filling it, which provided a surprising sense of ownership around this work and this newly mapped place.

… See full entry