After the first year of observations with the GRAVITY fringe tracker, we compute correlations between the optical path residuals and atmospheric and astronomical parameters. The median residuals of the optical path residuals are 180 nm on the ATs and 270 nm on the UTs. The residuals are uncorrelated with the target magnitudes for Kmag below 5.5 on ATs (9 on UTs). The correlation with the coherence time is however extremely clear, with a drop-off in fringe tracking performance below 3 ms.
@article{arxiv.1806.10858,
title = {The GRAVITY fringe tracker: correlation between optical path residuals and atmospheric parameters},
author = {S. Lacour and R. Dembet and R. Abuter and P. Fedou and G. Perrin and F. Eisenhauer and K. Perraut and C. Straubmeier and W. Brandner and A. Amorin and the GRAVITY collaboration},
journal= {arXiv preprint arXiv:1806.10858},
year = {2018}
}
Comments
submitted to SPIE Astronomical Telescopes & Instrumentation 2018