The first quantum clock was built in 1957. Its frequency standard was a maser based on a beam of ammonia molecules. Quantum clocks built later, which use a beam of cesium atoms as the frequency standard, do not require calibration against a standard, since the nominal value of the fundamenta...
We report an optical lattice clock with a total systematic uncertainty of 8.1 x 10 - 19 in fractional frequency units, representing the lowest uncertainty of any clock to date. The clock relies on interrogating the ultranarrow 1 S 0-* 3 P 0 transition in a dilute ensemble of fermionic stro...
atom–atom coherence times of 26 s, a 270-fold improvement over the measured atom–laser coherence time, demonstrate a relative instability of 9.7(4)×10−18/τ (where τ is the averaging time) and reach a relative statistical uncertainty of 8.9 × 10−20 after 3.3 h of ...
We take 0.1 ns as a conservative bound on the remaining uncertainty. We have calculated the correction due to the 3D1 hyperfine structure to be at the negligible 0.001% level. Therefore, we choose 0.1 ns as a comfortable upper bound on this effect. We quantify systematic bias from ...
We report on the progress of an optical clock based on an indium ion (In) sympathetically cooled with a calcium ion (Ca) in a linear trap. In our previous work, we have measured the clock transition frequency with an uncertainty of 5脳 10 15, prompting an update of the Comit茅 ...
When the conventional method of defining sequential element timing parameters is used in conjunction with the conventional method of accounting for clock uncertainty in timing analysis, the results are overly pessimistic because, when clock uncertainty is nonzero, the element can never be simultaneously ...
Additional Uncertainty Clock Latency at the Source MMCM External Feedback Loop Delay Constraining Input and Output Ports System Level Perspective Defining Input Delays Defining Output Delays Choosing the Reference Clock Identifying the Clocks Related to Each Port ...
Further we confirm that a BCO in a triangle is identical to the mean of the triangle delay mis- closures within the analysis uncertainty. It was recognised that the dominant effect for the occurrence of significant BCOs comes from the ionospheric delay calibration. As soon as the delay ...
MacOS screen saver to display time in the form of literary quotes. Based on way cooler https://www.instructables.com/id/Literary-Clock-Made-From-E-reader/ - LiteraryClockScreenSaver/litclock_annotated.csv at 08533d79249171ce16ca7daabd6e3a804b2303d8 · mm
This will have a large impact on the planned dual frequency Satellite Based Augmentation Systems (SBAS). Once the ionospheric delay error uncertainty is removed, the Protection Levels will decrease substantially, and other error sources will dominate. The remaining terms in the error bound are much...