Journal ArticleDOI
Carrier-phase time transfer
Kristine M. Larson,Judah Levine +1 more
TLDR
GPS carrier-phase time transfer is more than an order of magnitude more precise than GPS common view time transfer and agrees, within the experimental uncertainty, with two-way satellite time-transfer measurements for a 2400 km baseline.Abstract:
We have conducted several time-transfer experiments using the phase of the GPS carrier rather than the code, as is done in current GPS-based time-transfer systems. Atomic clocks were connected to geodetic GPS receivers; we then used the GPS carrier-phase observations to estimate relative clock behavior at 6-minute intervals. GPS carrier-phase time transfer is more than an order of magnitude more precise than GPS common view time transfer and agrees, within the experimental uncertainty, with two-way satellite time-transfer measurements for a 2400 km baseline. GPS carrier-phase time transfer has a stability of 100 ps, which translates into a frequency uncertainty of about two parts in 10/sup -15/ for an average time of 1 day.read more
Citations
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Journal ArticleDOI
Comparison between frequency standards in Europe and the USA at the 10-15 uncertainty level
Andreas Bauch,J. Achkar,Sébastien Bize,Davide Calonico,R Dach,R Hlavac,Luca Lorini,Thomas E. Parker,Gérard Petit,Dirk Piester,Krzysztof Szymaniec,P. Uhrich +11 more
TL;DR: In this article, the authors performed a comparison campaign of selected frequency references maintained in their laboratories during about 25 days in October/November 2004, using two-way satellite time and frequency transfer (TWSTFT) in an intensified measurement schedule of 12 equally spaced measurements per day.
Journal ArticleDOI
Improved frequency measurement of a one-dimensional optical lattice clock with a spin-polarized fermionic $^{87}$Sr isotope
TL;DR: In this paper, a spin-polarized fermionic isotope was designed to realize a collision-shift-free atomic clock with neutral atom ensembles, and the absolute frequency of the clock transition was determined as 429,228,004,229,875(4) Hz, where the uncertainty was mainly limited by the frequency link.
Time and Frequency Measurements Using the Global Positioning System (GPS)
TL;DR: This paper discusses how a GPS receiver can provide a reference signal for frequency calibrations and time synchronization, and explains the several types of time and frequency measurements that utilize GPS signals.
Journal ArticleDOI
Improved Frequency Measurement of a One-Dimensional Optical Lattice Clock with a Spin-Polarized Fermionic 87Sr Isotope
TL;DR: In this paper, a one-dimensional optical lattice clock with a spin-polarized fermionic isotope was proposed to realize a collision-shift-free atomic clock with neutral atom ensembles.
Journal ArticleDOI
IGS/BIPM pilot project: GPS carrier phase for time/frequency transfer and timescale formation
TL;DR: The jointly sponsored `IGS/BIPM Pilot Project to Study Accurate Time and Frequency Comparisons using GPS Phase and Code Measurements' is developing operational strategies to exploit geodetic GPS methods for improved global time/frequency comparisons to the mutual benefit of both organizations.
References
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Book
Global Positioning System: Theory and Practice
TL;DR: In this paper, the origins of GPS are discussed and the development of global surveying techniques are discussed. But the authors focus on the use of global positioning techniques and do not address the issues of accuracy and access of GPS data.
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Global mapping functions for the atmosphere delay at radio wavelengths
TL;DR: In this article, the authors developed expressions for calculating the ratios (mapping functions) of the "line of sight" hydrostatic and wet atmospheric path delays to their corresponding zenith delays at radio wavelengths for elevation angles down to 3°.
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Contributions to the theory of atmospheric refraction
TL;DR: In this paper, it was shown that the height integral of the atmospheric refractivity for light, taken from ground level up to the top of the atmosphere, is directly proportional to ground pressure.
Journal ArticleDOI
An Automatic Editing Algorithm for GPS data
TL;DR: An algorithm has been developed to edit automatically Global Positioning System data such that outlier deletion, cycle slip identification and correction are independent of clock instability, selective availability, receiver–satellite kinematics, and tropospheric conditions.