38th International Cosmic Ray Conference (ICRC2023), 26 July - 3 August, 2023, Nagoya, Japan.Mykhailo Dalchenko and Matthieu Heller on behalf of the CTA-LST Project.
Luis del Peral Gochicoa, Jose Julio Lozano Bahilo and Maria Dolores Rodriguez Frias belong to the CTA-LST Project.We present a new approach to the pointing determination of Imaging Atmospheric Cherenkov
Telescopes (IACTs). This method is universal and can be applied to any IACT with minor
modifications. It uses the trajectories of the stars in the field of view of the IACT’s main camera
and requires neither dedicated auxiliary hardware nor a specific data taking mode. The method
consists of two parts: firstly, we reconstruct individual star positions as a function of time, taking
into account the point spread function of the telescope; secondly, we perform a simultaneous
fit of all reconstructed star trajectories using the orthogonal distance regression method. The
method does not assume any particular star trajectories, does not require a long integration time,
and can be applied to any IACT observation mode. The performance of the method is assessed
with commissioning data of the Large-Sized Telescope prototype (LST-1), showing the method’s
stability and remarkable pointing performance of the LST-1 telescope
