Folks, there are myriad ways to do navigation. For those living close enough to a US coastline, Loran C is available and can be used in the greater Puget Sound Region, New York Metro, DC, New Orleans, Miami, Houston, LA, San Francisco, just to name a few. Orienting the Loran output to a land map is no longer an issue. Then there are all sorts of terrestrial beaconing systems at our disposal. You just need the tech to tap into them. Back in the 80s we put together an entire network that we could find any metro bus anywhere in King or Pierce County using nothing more than an array of terrestrial beacons we put up ourselves. It wouldn't be that hard to tap into that sort of technology these days. It wouldn't be too hard or expensive to do the same with a set of community repeaters and a df kit for that matter.

As far as celestial nav goes, isn't number crunching what we got these wonderful machines for? I am sure there are already optical input devices that make celestial nav using a laptop pretty much an exact science. I just bet with the right video input a good program could compensate for all sorts of variables enough to give you a true fix.

We set up a laser nav system one time using two different colored lasers set parallel from two known fixed locations overlooking a city. From anywhere in town you could see both beams, you could fairly easily calculate your location relative to the points of origin. We figured that was good for at least 100 square miles.