Take a good hard look at the GPS interface specification. The GPS satellites aren't synchronized with each other*. They are synchronized with the ground contr

Take a good hard look at the GPS interface specification. The GPS satellites aren't synchronized with each other*. They are synchronized with the ground control segment. https://www.gps.gov/technical/icwg/IS-GPS-200K.pdf https://www.gps.gov/technical/icwg/IS-GPS-200K.pdf * recent satellites have limited autonomous navigation capability as a backup.