The laser tracker allows the precise determination of positions of surfaces in three dimensions over volumes
exceeding 30 m radius from the tracker head. At the Large Binocular Telescope a laser tracker has recently been
employed for the initial alignment of all telescope optics in the right hand side (DX) bent Gregorian optical train. In this
paper the particular approach to alignment of optical elements employed during this campaign is discussed in detail,
together with results and expected accuracies. Subsequent to this "mechanical alignment" the telescope was taken "onsky"
and a subsequent "optical alignment" using a Shack-Hartman wavefront sensor with stellar sources took place.
Ongoing activities include using the laser tracker to measure elevation and thermally induced displacements of
individual optical elements.
A. Rakich, A. Rakich,
"Alignment of LBT optics using a laser tracker", Proc. SPIE 7733, Ground-based and Airborne Telescopes III, 77335K (6 August 2010); doi: 10.1117/12.856275; https://doi.org/10.1117/12.856275