Since 2016 GMT have been developing a telescope metrology system, that is intended to close the gap between openloop modelling and AGWS operations. A prototyping campaign was initiated soon after receipt of laser metrology hardware in 2017. This campaign is being conducted in collaboration with the Large Binocular Telescope Observatory (LBTO), and hardware was first deployed on the LBT in August 2017. Since that time the system had been run and developed over some hundreds of hours on-sky. It has been shown to be capable of reliably measuring the relative positions of the main optics over ~ 10 m to a repeatability of ~ 1-2 microns RMS. This paper will describe the prototyping campaign to date, the basic design of the system, lessons learned and results achieved. It will conclude with a discussion of future prototyping efforts. |
|