I’ve been spending a lot of time thinking about ViaGrid^{1 2}, a standard for rapid PCB manufacturing. Current UV DPSS fiber lasers have the ability to ablate copper on FR4 really well, hitting trace/space marks comparable to commercial fabs. However, there isn’t a good way to make vias at home. The idea of ViaGrid is to pre-manufacture a bunch of boards with vias already in place, so that you can later isolate them and incorporate them into your designs. This is a really interesting thing for a makerspace to have: the ability to rapidly create new PCBs in-house with design rules similar to production boards. My two local makerspaces^{3 4} have plenty of members doing PCB work, and I think an end-to-end class where you can make boards in one sitting would be compelling, and get more people designing and manufacturing their own circuit boards. One question that stood out to me was: what’s the right size viagrid board? How many vias is enough? How big should it be? I got curious and wanted to compute some statistics.

I am always excited when I see a post from Mark Litwintschik on Hacker News; I know that means I’m going to learn about a cool new GIS dataset. When I saw his post about the The World’s 2.75B Buildings, I knew I was in for a treat.

The Dataset

Mark’s blog entry talks about the Global Building Atlas, a project from researchers at the Technical University of Munich to document every building on the surface of the earth. They developed an open-source pipeline to detect buildings from Planet Labs’ satellite imagery. I like this methdology because it has no regional bias; if this was a patchwork of national datasets, it might be simpler to create, but the data quality would vary depending upon the country of origin.