Re:GPS overrated? (Score 1)

There is something called pressure navigation which depends upon the predictability of the winds across isobars to correct for crosswinds. By plugging the at-altitude atmospheric pressure and latitude, you can calculate the drift that would result if you held a straight-line course between the two points. Correct for the drift and hold that exact heading for the entire trip.

I've always meant to try this out some day, but have not gotten around to it yet. Of course this technique doesn't compensate for natural and man-made obstacles, especially the Temporary Flight Restrictions that follow the President around as he raises funds.