One thing that caught me as interesting about the article was the obstruction map and what could be achieved with that kind of data if it was gathered and corre

One thing that caught me as interesting about the article was the obstruction map and what could be achieved with that kind of data if it was gathered and correlated with millions of other users. I am no expert but it seems that traditional observation from space has always been limited by the resolution from up on high. Flip the problem and have ground-based observers in densely populated areas track shadows in a rotating grid of point sources in the sky, and you can build a 3d map outwards instead, the only problem being how to increase the density, consistency, and spread of the ground-based sensor array.