3. Measuring Delta-t Accurately, Possible Errors
- Error of 0.001 sec in delta-t = 200 miles !
- Satellites have very accurate (expensive) Atomic Clocks.
- Receivers could use same clocks - but would be expensive
($50k - $100k).
- Receivers use 4 satellites to sync their time to universal
time. (If three satellites can define a point, then a fourth should go
through the same point if all times were correct.Use error as a correction
to receiver time).