We present in this paper the design and characterisation of a new sub-system of the VLTI 2nd generation instrument GRAVITY: the Calibration Unit. The Calibration Unit provides all functions to test and calibrate the beam combiner instrument: it creates two artificial stars on four beams, and dispose of four delay lines with an internal metrology. It also includes artificial stars for the tip-tilt and pupil guiding systems, as well as four metrology pick-up diodes, for tests and calibration of the corresponding sub-systems. The calibration unit also hosts the reference targets to align GRAVITY to the VLTI, and the safety shutters to avoid the metrology light to propagate in the VLTI-lab. We present the results of the characterisation and validtion of these differrent sub-units.
Cite
@article{arxiv.1407.6660,
title = {GRAVITY: the Calibration Unit},
author = {N. Blind and F. Eisenhauer and M. Haug and S. Gillessen and M. Lippa and L. Burtscher and O. Hans and F. Haussmann and S. Huber and A. Janssen and S. Kellner and Y. Kok and T. Ott and O. Pfuhl and E. Sturm and J. Weber and E. Wieprecht and A. Amorim and W. Brandner and G. Perrin and K. Perraut and C. Straubmeier},
journal= {arXiv preprint arXiv:1407.6660},
year = {2014}
}
Comments
12 pages, 11 figures. Proceeding of SPIE 9146 "Optical and Infrared Interferometry IV"