It works up to 3000km with full precision, you just need a receiver without CoCom limits. (actually, precision should be better without atmosphere). It also wor

It works up to 3000km with full precision, you just need a receiver without CoCom limits. (actually, precision should be better without atmosphere). It also works all the way up to geostationary orbit, but with some limitations. https://www.gps.gov/multimedia/presentations/2011/09/ICG/miller.pdf https://www.gps.gov/multimedia/presentations/2011/09/ICG/mil...