Metrology for Long Distance Surveying: A Joint Attempt to Improve Traceability of Long Distance Measurements

Pollinger, Florian; Bauch, A.; Meiners-Hagen, Karl; Astrua, Milena; Zucco, Massimo; Bergstrand, Sten; Görres, Barbara; Kuhlmann, Heiner; Jokela, Jorma; Kallio, Ulla; Koivula, Hannu; Poutanen, Markku; Neyezhmakov, Pavel; Kupko, V. S.; Merimaa, Mikko; Niemeier, Wolfgang; Saraiva, F.; Schön, Steffen; Berg, S. A. van den; Wallerand, Jean‐Pierre

doi:10.1007/1345_2015_154

Cited by 13 publications

(10 citation statements)

References 13 publications

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“…In October 2013, we conducted a measurement campaign at the Physikalisch Technische Bundesanstalt (PTB), Germany's national metrology institute in Braunschweig. The setup was operated in the context of the research project "Surveying" funded by the European Metrology Research Program (Pollinger et al, 2015). Various receiver antenna combinations were operated at the Meitner and Kopfermann building over three weeks.…”

Section: Methodsmentioning

confidence: 99%

The Atmospheric Scale Lengths of Turbulence and Its Dependencies Derived from GPS Single Difference with a Common Clock

Kermarrec

Schön

2021

Preprint

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Signals from Global Navigation Satellite Systems are influenced by random variations of the refractivity index as they travel through the troposphere • The power spectral density of positioning residuals from Single Differenced phase observations allows studying key parameters of tropospheric turbulence• The cutoff at low frequency show daily variations whereas the outer scale length can be considered as an atmospheric constant of the order of 3000m Abstract Microwave signals, for example, those from Global Navigation Satellite Systems (GNSS) and very long baseline interferometry, are affected by tropospheric turbulence in such a way that the random fluctuations of the atmospheric index of refraction correlate the phase measurements. These atmospheric correlations are an important error source in space geodetic techniques. For computational reasons, they are neglected in positioning applications, to the detriment of a trustworthy description of the precision, and rigorous test statistics. Fortunately, modelling such correlations is possible by combining concepts from electromagnetic wave propagation in a random medium and the Kolmogorov turbulence theory. In this contribution, we will process single differences GNSS phase observations from a 300 m baseline between two different receivers linked to a common clock. After a preprocessing to filter additional error contributions, such as multipath, we will study the power spectral density of the phase residuals. We will estimate its low and high cutoff frequencies with an adapted unbiased Whittle maximum likelihood estimator. These cutoff frequencies -as predicted by turbulence theory -are related directly to the scale lengths of turbulence, i.e. the size of the eddies that correlate the GNSS observations. The study of their dependencies with the satellite geometry, day of the year, or time of the day provides new insights into the two-and three-dimensional atmospheric turbulence in the atmosphere. In addition, it contributes to improving the stochastic description of random effects impacting GNSS phase observations.

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Section: Methodsmentioning

confidence: 99%

The Atmospheric Scale Lengths of Turbulence and Its Dependencies Derived from GPS Single Difference with a Common Clock

Kermarrec

Schön

2021

Preprint

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“…The eight Ashtech Dorne Margolin Choke Ring antennas in our validation experiment were calibrated by Geo++ in 2009, and as part of the EMRP SIB60 project (Pollinger et al 2015), at Hannover University IfE using the robot calibration, and at Bonn University in the anechoic chamber, in 2013-2014 (Table 2). Besides three individual absolute calibration sets, we used IGS08-1816 (Schmid et al 2015) type absolute calibration tables for the antennas.…”

Section: Measurements In 2014mentioning

confidence: 99%

“…We developed the method further in 2011 (Kallio et al 2012) and during the EMRP SIB60 project (Pollinger et al 2015) by increasing the number of permutations and sessions, and thus the redundancy of the observations. We used the version developed in a Metsähovi antenna test in 2011 (Kallio et al 2012) and introduced it as a permutation method.…”

Section: Introductionmentioning

confidence: 99%

Validating and comparing GNSS antenna calibrations

Kallio

Koivula

Lahtinen

et al. 2018

J Geod

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GNSS antennas have no fixed electrical reference point. The variation of the phase centre is modelled and tabulated in antenna calibration tables, which include the offset vector (PCO) and phase centre variation (PCV) for each frequency according to the elevations and azimuths of the incoming signal. Used together, PCV and PCO reduce the phase observations to the antenna reference point. The remaining biases, called the residual offsets, can be revealed by circulating and rotating the antennas on pillars. The residual offsets are estimated as additional parameters when combining the daily GNSS network solutions with full covariance matrix. We present a procedure for validating the antenna calibration tables. The dedicated test field, called Revolver, was constructed at Metsähovi. We used the procedure to validate the calibration tables of 17 antennas. Tables from the IGS and three different calibration institutions were used. The tests show that we were able to separate the residual offsets at the millimetre level. We also investigated the influence of the calibration tables from the different institutions on site coordinates by performing kinematic double-difference baseline processing of the data from one site with different antenna tables. We found small but significant differences between the tables.

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“…The time of flight definition of the length unit can directly be used for long range measurements, like e.g. lunar laser ranging [140] or long distance metrology in geodesy [147] and large scale manufacturing [167]. For applications in normal laboratory and manufacturing environment, since time-of-flight measurements do not provide the necessary accuracy over smaller lengths, interferometric length measurements based on recommended stabilized light sources offer smallest uncertainties.…”

Section: Historical Evolution Of the System Of Unitsmentioning

confidence: 99%

Contributions of precision engineering to the revision of the SI

et al. 2017

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All measurements performed in science and industry are based on the International System of Units, the SI. It has been proposed to revise the SI following an approach which was implemented for the redefinition of the unit of length, the metre, namely to define the SI units by fixing the numerical values of so-called defining constants, including c, h, e, k and NA. We will discuss the reasoning behind the revision, which will likely be put into force in 2018. Precision engineering was crucial to achieve the required small measurement uncertainties and agreement of measurement results for the defining constants

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Metrology for Long Distance Surveying: A Joint Attempt to Improve Traceability of Long Distance Measurements

Cited by 13 publications

References 13 publications

The Atmospheric Scale Lengths of Turbulence and Its Dependencies Derived from GPS Single Difference with a Common Clock

The Atmospheric Scale Lengths of Turbulence and Its Dependencies Derived from GPS Single Difference with a Common Clock

Validating and comparing GNSS antenna calibrations

Contributions of precision engineering to the revision of the SI

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