Besides the Russian GLONASS, the Europeans are supposed to be building a completely superfluous Galileo system. Dunno what Glonass is worth.
I read someplace that that 4-Corners monument is misplaced. It's on the Navajo Nation reservation and there's a toll gate, off US-160, as well as a lot of booths selling Indian handicrafts. The brass strip running through Flamsteed House, the Old Royal Observatory, in Greenwich by London, that shows the Prime Meridian, Long. 0, is also supposed to be out by 100 m. or so. Odd. The 180 Meridian, opposite, runs through Taveuni in Fiji; I haven't been there so don't know if it's marked. Can't walk from Su. to Mon. as they cheated and bent the International Date Line around the islands. I wonder how accurate the "Mitado del Mundo" monument in Ecuador and a sign for the Equator in Kenya are; I've been past the latter on a bus. Also one for the Tropic of Capricorn just S. of Rockhampton Qld. 4700.
Finally, I wonder how long. is determined on other bodies. You have to pick a prime or 0 meridian, so I wonder what this is. Latitude, of course, is determined by the object's spin.