Continuous time transfer using GPS carrier phase

Dach, Rolf; Schildknecht, Thomas; Springer, T.; Dudle, G.; Prost, L.

doi:10.1109/tuffc.2002.1049729

Cited by 24 publications

(13 citation statements)

References 5 publications

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“…In general, both maser clocks indicate smooth offset data with small fluctuations. This might be due to noise in the GNSS signal, maser instrumentation and thermal variations among other things that result in fluctuation as explained in Allan and Weiss (1980) and Dach et al, (2002 (Goujon et al, 2010). Hence it is important to keep the storage room at a constant temperature to minimise frequency fluctuations.…”

Section: Resultsmentioning

confidence: 99%

Analysis of the performance of hydrogen maser clocks at the Hartebeesthoek Radio Astronomy Observatory

Munghemezulu¹,

Combrinck²,

Botai³

et al. 2016

SA J of Geomatics

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Section: Resultsmentioning

confidence: 99%

Analysis of the performance of hydrogen maser clocks at the Hartebeesthoek Radio Astronomy Observatory

Munghemezulu¹,

Combrinck²,

Botai³

et al. 2016

SA J of Geomatics

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“…Finally correlation between the ambiguity terms and the clock errors, which weakens the ability of carrier phase methods to resolve absolute differences from system time (Dach et al 2002), would need to be addressed.…”

Section: Discussionmentioning

confidence: 99%

“…As the problem domain amounts to determining the offset of a local clock from system time then analogous work has been done in time transfer studies using GPS and GLONASS, although the latency and accuracy requirements are significantly different on the whole. Dach et al (2002) discuss the usage of both carrier phase and pseudorange for post-processed time transfer and make the key point that phase observations alone cannot resolve absolute offsets from system time because of correlation between the phase ambiguity terms and the clock offsets. Ray and Senior (2005) gives a good overview of the current state of play in geodetic time transfer techniques using GPS.…”

Section: Introduction and Problem Statementmentioning

confidence: 99%

Single epoch estimation of the Galileo integrity chain sensor station clock offsets

et al. 2007

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The Galileo integrity chain depends on a number of key factors, one of which is contamination of the signal-in-space errors with residual errors other than imperfect modelling of satellite orbits and clocks. A potential consequence of this is that the user protection limit is driven not by the errors associated with the imperfect orbit and clock modelling, but by the distortions induced by noise and bias in the integrity chain. These distortions increase the minimum bias the integrity chain can guarantee to detect, which is reflected in the user protection limit. A contributor to this distortion is the inaccuracy associated with the estimation of the offset between the Galileo sensor station (GSS) receiver clocks and the Galileo system time (GST). This offset is termed the receiver clock synchronization error (CSE). This paper describes the research carried out to determine both the CSE and its associated error using GPS data as captured with the Galileo System Test Bed Version 1 (GSTB-V1). In the study we simulate open access to a time datum using IGS data. Two methods are compared for determining CSE and the corresponding uncertainty (noise) across a global network of tracking stations. The single-epoch single-station method is an 'averaging' technique that uses a single epoch of data, and is carried out at individual sensor stations, without recourse to the data from other stations. The global network solution method is also single epoch based, but uses the inversion of a linearised model of the global system to solve for the CSE simultaneously at all GSS along with a number of other parameters that would otherwise be absorbed into the CSE estimate in the averaging technique. To test the effectiveness of various configurations in the two methods the estimated synchronisation errors across the GSS network (comprising 25 stations) are compared to the same values as estimated by the International GPS Service (IGS) using a global tracking network of around 150 stations, as well as precise orbit and satellite clock models determined by a combination of global analysis centres. The results show that the averaging technique is vulnerable to unmodelled errors in the satellite clock offsets from system time, leading to receiver CSE errors in the region of 12 ns (3.7 m), this value being largely driven by the satellite CSE errors. The global network approach is capable of delivering CSE errors at the level of 1.5 ns (46 cm) depending on the number of parameters in the linearised model. The International GNSS Service (IGS) receiver clock estimates were used as a truth model for comparative assessment.

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“…The GPS data were analyzed in 3-day batches with 24-hour overlaps used to remove discontinuities at the day boundaries [14]. Recent studies suggest that the day boundary discontinuities should be left in the GETT time series.…”

Section: Gett Data Analysismentioning

confidence: 99%

“…In order to use the USN1 receiver calibration, we computed a multiday local clock tie between USNO and USN1 using GETT. A conservative estimate of the tie accuracy is 0.2 ns [14]. For calculations of Allan Deviation (ADEV) and Time Deviation (TDEV) at USNO, AMC2, and NIST, we converted timing estimates to maser ensembles.…”

Section: Comparisons With Twstftmentioning

confidence: 99%

Long-term comparisons between two-way satellite and geodetic time transfer systems

Plumb

Larson

2005

IEEE Trans. Ultrason., Ferroelect., Freq. Contr.

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Global Positioning System (GPS) observations recorded in the United States and Europe were used to evaluate time transfer capabilities of GETT (geodetic time transfer). Timing estimates were compared with twoway satellite time and frequency transfer (TWSTFT) systems. A comparison of calibrated links at the U.S. Naval Observatory, Washington, D.C., and Colorado Springs, CO, yielded agreement of 2.17 ns over 6 months with a standard deviation of 0.73 ns. An uncalibrated link between the National Institute of Standards and Technology (NIST) and Physikalisch-Technische Bundesanstalt, Braunschweig, Germany, has a standard deviation of 0.79 ns over the same time period.

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Continuous time transfer using GPS carrier phase

Cited by 24 publications

References 5 publications

Analysis of the performance of hydrogen maser clocks at the Hartebeesthoek Radio Astronomy Observatory

Analysis of the performance of hydrogen maser clocks at the Hartebeesthoek Radio Astronomy Observatory

Single epoch estimation of the Galileo integrity chain sensor station clock offsets

Long-term comparisons between two-way satellite and geodetic time transfer systems

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