A laser-tracker-target fiducialized alignment telescope for astronomical telescope alignment

Laser trackers and autostigmatic microscopes/telescopes both represent the "best-in-class” instruments for the types of measurement that they are designed for. While laser trackers allow the very precise determination of objects locations and orientations, laser trackers cannot easily measure general optical properties of optical elements and systems. Alignment telescopes can easily measure various properties of optical surfaces such as surface tilts, centre of curvature locations, optical axes etc., but it is difficult to refer these measurements to mechanical data. By determining the optical axis of an alignment telescope with a laser tracker measurement, it is possible to link the capabilities of these two metrology systems. This allows types of measurement that neither a laser tracker nor an alignment telescope are capable of independently of each other. This paper describes results of experiments that test the accuracy with which a laser tracker can capture the optical axis of an alignment telescope. It is found that accuracies of < 1 arcseconds optical axis recovery with a laser tracker are achievable.