The Measurement of Shifting of the Optic Axis of the YNAO 1m Solar Telescope

In the tracking process of the YNAO 1m solar telescope, a deviation between the optic axes of the telescope and its guiding telescope will affect the auto-guiding tracking. This paper analyzes such a deviation with numerical simulation and measurement. We first introduce the basic structure of the 1m solar telescope and the auto-guiding system, set up the model for the telescope tube through the finite-element method, derive the relation of the deflection angle versus the altitude of the telescope, and simulate the track of a stellar image affected by the deflection angle. Considering the structure of the entire telescope, we propose a method for measuring a deviation between the optic axes to obtain the relation between the deflection angle and altitude. We finally use some observed data to find actual values of the relation.