On Fri, Mar 18, 2011 at 8:31 PM, jimlux <[email protected]> wrote: > >> That's an interesting idea, but I think all the orbit data for GPS >> satellites >> is Earth relative rather than star relative. I wonder if the group that >> drives the GPS satellites even knows their location relative to the stars. >> I'll bet not. >> > > I'll bet they do. Lots of earth orbiting satellites use star trackers for > position determination.
Star trackers or Sun sensors are used for pointing, They measure rotation but not position. It is at least conceptually easy to measure a GPS sat's location if you have a GPS receiver at a surveyed location. And also they have access to the encrypted military band we don't so they can correct for atmospheric effects. I think in addition the GPS sats get observed optically too > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > -- ===== Chris Albertson Redondo Beach, California _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
