Known primarily as a navigation system, the global positioning system is also used to disseminate precise time, time intervals, and frequency. The GPS
carrier signals originate from on-board atomic clocks monitored by ground control stations. GPS satellites transmit time signals with each subframe of data modulated onto the carrier. While navigation and survey receivers use GPS time
to aid in computation of position solutions, time and frequency receivers use GPS satellite transmissions to control timing signals and oscillators.
Accuracy of timing disseminated from L1 GPS receivers on determined positions is about 30 nanoseconds (@95% probability level) @ one satellite in view. Employment of more complex methods may bring accuracy to even less than 1 nanosecond.
In GPS we have two types of receivers:
1. for positioning
2. for time transfer signals
The first one does not guarantee such level of time accuracy. They are only designed for positioning.
The second one don't present position, but guarantee high level of time signals.
cezary
Than you for your answer.
Dear all, do you have some papers on the GPS accuracy?
Dear Vicenzo, since I don't know what exactly is your goal, try as first these two:
Best, Franc
Did you research something about DCB values for satellites and receivers?
To Mustafa
My answer is: NO.
I am interesting on the time synchronization among nodes in Sensor Network. Many papers deal the synchronization using GPS signal but without information on time accuracy.
For example for smart grid it is very important the synchronization among PMUs:
Synchrophasor technologies and systems use monitoring devices called phasor measurement units (PMUs) that measure the instantaneous voltage, current, and frequency at specific locations in an electric power transmission system. The sampling of these parameters takes place 20 or more times per electrical cycle which is 1200 or more times per second. PMUs convert the measured parameters into phasor values, typically 30 or more values per second. The PMUs also add a precise time stamp to these phasor values turning them into synchrophasors. The time-stamping allows these phasor values, which are provided by PMUs in different locations and across different power industry organizations, to be correlated and time-aligned and then combined. The resulting product enables transmission grid planners and operators to have a high-resolution “picture” of conditions throughout the grid.
- Badges
- Science topic
- Similar topics
- Names