Comment on ‘Relativistic theory of the falling retroreflector gravimeter’

@article{Ken2018CommentO,
  title={Comment on ‘Relativistic theory of the falling retroreflector gravimeter’},
  author={Petr Křen and Vojtech P{\'a}link{\'a}s̆},
  journal={Metrologia},
  year={2018},
  volume={55},
  pages={314-315}
}
In the paper by Ashby (2018 Metrologia 55 1?10) the correction due to the time delay of light propagated through the prism retroreflector of absolute gravimeters is discussed. Accordingly, the correction of about???6.8 ?Gal should be applied for a typical gravimeter such as the most precise FG5(X) gravimeter declaring standard uncertainty at the level of 2 ?Gal. In consequence, the present gravimetric results related to the Kibble balance or the global absolute gravity reference system should… 
Reply to ‘Comment on Relativistic theory of the falling cube gravimeter’
In the subject paper [1] of the comment [2], light propagation through an absolute gravimeter was analyzed, including the propagation delay through the falling retroreflector and through the vacuum.
Relativistic theory of the falling retroreflector gravimeter
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The signal recorded in absolute ballistic gravimeters and used to track the trajectory of the free-falling corner-cube was recently studied for the first time in full agreement with relativistic
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We have assessed the implications of the in-cube light propagation effect in absolute gravimeters, and found it contradictory to existing theoretical and experimental data. We maintain that the

References

SHOWING 1-3 OF 3 REFERENCES
Relativistic theory of the falling retroreflector gravimeter
We develop a relativistic treatment of interference between light reflected from a falling cube retroreflector in the vertical arm of an interferometer, and light in a reference beam in the
On the influence of the rotation of a corner cube reflector in absolute gravimetry
Test masses of absolute gravimeters contain prism or hollow retroreflectors. A rotation of such a retroreflector during free-fall can cause a bias in the measured g-value. In particular, prism
Balancing a retroreflector to minimize rotation errors using a pendulum and quadrature interferometer.
TLDR
A novel way to achieve the collocation by incorporating the proof mass into a pendulum and using a quadrature interferometer to interrogate its apparent translation in its twist mode is described, allowing an order of magnitude improvement over traditional methods of balancing.