Salute!
What a change in just 50 years. Number one was incredible accuracy of our clocks.
The "longitude problem" was a bear. The lattitude easy peasy. So the navigators from the middle ages to nearly the 20th century had trouble knowing how far east or west they were. With the watch I wear now, those folks in 1500, 1600, 1700 would have no problem. And the reason our GPS we have in our cellphone is so great is we can deal with nanoseconds versus minutes!
I do not trust the satellite systems in war. But with the great INS systems we now have and super accurate clocks, I have a good feeling. Of course there are still doppler systems that are independent of radio and satellite systems.
Gums sends...