- GPS can be a reliable timekeeping source
- GPS must correct for relativistic time dilation -- about 38 microseconds a day
- Enhancements to GPS
- Differential GPS (DGPS)
- Wide-Area Augmentation System (WAAS)
- European Geostationary Navigation Overlay (EGNOS)
- Other global positioning systems
- LORAN-C
- GLONASS
- Gailleo (due in 2007)
|