Such system already exists, is called IMES, uses L1 band and is supported by standard Ublox 8 firmware. http://gpsworld.com/wirelessindoor-positioningopening-up-indoors-11603/ Leo > From: Stewart Cobb <stewart.cobb@gmail.com> > Peter Reilley suggests a backup to GPS using terrestrial transmitters. This > idea has been around since the early days of GPS....

Hi But, by their nature, not useful for timing or precision navigation. They are simply a solution to the “feed you coupons at the mall” issue. Since they run as an independent system (they have their own ID’s) the direct “pollution” issue on a GPSDO is eliminated. You still have the previously mentioned receiver dynamic range questions. Bob > On Mar 15, 2018, at 5:26 AM, Leo Bodnar <leo@leobodnar.com> wrote: > > Such system already exists, is called IMES, uses L1 band and is supported by standard Ublox 8 firmware. > > http://gpsworld.com/wirelessindoor-positioningopening-up-indoors-11603/ > > Leo > > >> From: Stewart Cobb <stewart.cobb@gmail.com> >> Peter Reilley suggests a backup to GPS using terrestrial transmitters. This >> idea has been around since the early days of GPS.... > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there.