We have now run three casual mapping parties in the “Social Mapping Sunday” series, and they are always a bit different but each one has been as fun as the last.

Shenton Park

In Shenton Park, lots of brand new mappers showed up and were introduced to OSM for the first time. About 13 of us in total! Meeting in the park and walking to nearby features to map worked well.

We didn’t come prepared with specific material to introduce new mappers, and we ended up spending a lot of time installing apps and setting up user accounts, etc. This was not a problem per-se, because it needs to be done. But it would have been smoother if we had a link to send people to which helped people get set up with the basics.

Mount Lawley

In Mount Lawley, 6 of us returning mappers set ourselves some explicit goals, and got a lot of data added to the map. We set the goal of mapping all of the shops and their names, footpaths, benches, bins, bus stops, bike parking and trees. We started in the middle of the shopping strip with a small team on each side of the road, and worked all the way to one end. Even though we didn’t map the whole retail strip, the are we did cover, we covered completely, which is very satisfying.

This gif shows the multiple stages of editing that these events encourage: The first step is cleaning up existing data and tracing features from imagery. This is important because it makes it easier to add data during the survey. It is also the best time to make assumptions based on the imagery, because any mistakes will be found during the survey. The next step is adding all of the data during the survey. The final step is cleaning things up, removing a few duplicates, fixing the odd tag, and generally making things neater with more powerful editing tools.

Organising

I have followed the same basic process that I described in my last post, for organising these events, but a few adjustments should be helpful. I have started a page on the wiki to document the process (in the hope that it continues to run, even when I can’t organise it).

It is important to do whole-group activities before everyone heads of to do mapping. That means before we start mapping we should: 1. take a photo of everyone, 2. decide on the details for the next event, and 3. decide on how to reconvene after mapping, for those who will stick around. Then 4. decide on mapping goals.

I have cobbled together a script for creating the before-and-after gifs showcased in this post. The most important part, is the awesome rendering engine Map Machine, which takes .osm files as input, so I can render the same area with the same settings passing in the data from different points in time (that I saved out of JOSM). I then use Image Magick’s convert to put the frames together into a gif.