Driving in high heeled shoes sound so awesomely stupid....
I probably would have hyphenated the compound adjective and pluralised sound, thus: Driving in high-heeled shoes sounds so awesomely stupid...
OK - and the beams from the satellite were relatively narrow. Or you needed the satellite to be at a particular range of azimuths? Sorry, altitudes.
Yes, a fix was only possible if the satellite was more than 15 degrees above the horizon.
just the old Navstar satellites which were in polar orbit so didn't provide fixes very often if you were near the equator.
Sorry, but why do you get fewer fixes near the equator? Were the orbits set up with apogee over the poles to provide more "hang time" in polar areas? I guess such a system would have been optimised for navigating nuclear-loaded bombers to their targets flying over the North Polar regions. It's not as if the system was designed for civilian convenience, after all.
No, the satellites were in polar orbits, which means they orbited in north-south direction following a particular meridian. Picture the meridians: they are further apart at the equator than the poles, hence fewer fixes.
No amount of careful planning will ever replace dumb luck.