GPS Time and frequency reference: GPS Disciplined Oscillators

GPS Time and frequency reference: GPS Disciplined Oscillators













Relative Accuracy of Various Frequency References
Reference     Modification                  Accuracy Range
Crystal                                                  1 to 100 ppm
Crystal         TCXO                            ~ 0.1 ppm
Crystal         Ovenized OXCO             0.001 - 0.1 ppm
Crystal         Double Oven                   ~ 50 ppt (parts per trillion)
Crystal         GPS supervised OXCO  ~ 5 ppt
Rubidium                                            ~ 50 ppt
Rubidium     GPS supervised              ~ 5 ppt
Cesium                                               0.01 to 0.1 ppt
Hydrogen Maser  Passive                  1 ppt
Hydrogen Maser  Active                      0.0007 ppt
ppt= parts per trillion, one part in 10(-12) = ns

One second per year =1/31,536000 = 0.000000031709792 = 3.2x10(-8) = 3.2 ppt








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https://rtklibexplorer.wordpress.com/resources/

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