- #1
SciencePF
- 56
- 0
Each of the 24 GPS satellites holds four atomic clocks! Why four and not one or two? They are not cheap!
Thanks
Thanks
Each GPS satellite needs four atomic clocks because it allows for accurate and reliable timekeeping. The atomic clocks are used to keep track of time and each satellite sends out signals that include the current time. Having four clocks ensures that even if one or two fail, the other clocks can still provide accurate time information.
The atomic clocks in a GPS satellite work by using the vibrations of atoms to keep track of time. The satellites use cesium or rubidium atoms, which are known to vibrate at a consistent rate. These vibrations are then used to generate an electrical signal that can be used to accurately measure time.
While technically one atomic clock could be enough for a GPS satellite, having four clocks ensures redundancy and improves the accuracy of the satellite's timing. With four clocks, any malfunction or drift in timekeeping of one clock can be detected and corrected by comparing it to the other three clocks.
The atomic clocks in a GPS satellite are synchronized using a process called clock offset calibration. This involves comparing the time signals from the atomic clocks to a master clock on the ground. Any differences in time are then used to adjust and synchronize the clocks on the satellite.
If one of the atomic clocks in a GPS satellite fails, the other three clocks can still provide accurate time information. However, the satellite's internal systems will detect the failure and compensate for it by adjusting the time signals from the remaining clocks. This ensures that the satellite continues to function properly and can still provide precise location and timing data.