Modeling for pointing of imaging atmospheric Cherenkov telescopes in TAIGA experiment

TAIGA-IACT telescopes are Imaging Atmospheric Cherenkov telescopes that are part of the hybrid experimental complex TAIGA, located 50 km from Lake Baikal in the Tunka Valley, Republic of Buryatia, Russia. The telescope operation requires accurate determination of the telescope direction and the position of a source on the camera plane. The telescope positioning system consists of stepper motors, shaft encoders, and a CCD camera mounted on the telescope dish. The position of the telescope is determined using shaft encoders with a pointing model, as well as using CCD camera images by astrometry of the sky region. The positions of sources on the telescope camera are calculated using the camera model and the estimated telescope direction. The telescope focal plane rotation angle is calculated by knowing the telescope pointing model parameters. This paper presents the developed models and methods used for the TAIGA-IACT telescope pointing.