15 Facts About China

[Hoosier]

I'm guessing the Mach 10 speeds referenced here happen when it's in the exosphere.

I didn't know China had it's own GPS, but I know that Japan has a localized one, Russia has a lower-resolution global system called GLONASS, and the EU Galileo project is still moving forward. Galileo should provide the best resolution yet, at least until the next generation NavStar birds are up.

Also differential GPS, essentially multiple GPS units in known locations on a vessel can produce accuracy under a foot.... I just found that out the other week.

[Ridge]

I'm guessing the Mach 10 speeds referenced here happen when it's in the exosphere.

That is pretty much the only time it would be possible to get a missile up to that kind of speed. And that would put it too close to the GPS satellites to be accurate. And it could not very well evade our radar from an altitude of 30 miles...