I suppose our hobby is related to the hobby of ground-to-ground long-distance observation. Except we don't perform the actual observation, just the math of where it is theoretically feasible :-) In my case, years ago, I did exactly the same as Tom and Ryan: I algorithmically searched for the longest sightline. It was a weekend project just to satisfy my curiosity. Then last year, Tom and I kinda connected informally over this hobby.