I Simposio de Postgrado 2023. Ingeniería, ciencias e innovación

I SIMPOSIO 2023 AN ASTROMETRIC LIMIT STUDY USING AN ANALOGOUS FAR-STELLAR FIELD EXPERIMENT WITH OPTICAL LITHOGRAPHY PHOTO-MASKS ABSTRACT In the astronomy branch of astrometry, the telescopes and instruments achievable precision determine the observations characteristics that can be made. To describe the performance of these optical systems, astronomers use the Cramer-Rao limit, a theoretical limit based on the ideal characteristics of the telescope and the (optical) detector. This limit has been, however, rarely tested on real-life systems. For a more reliable characterization of CMOS (and CCD) detectors, an optical experiment is proposed, using a custom-made photo-mask manufactured with optical lithography fabrication procedures. This opaque mask with transparent micrometric holes simulates a far-stellar field, producing a point-like sources array of light coming from an LED behind it. Using state of the art localization algorithms, the experimental astrometric limit can be estimated with different statistical tools, fitting a Gaussian profile instead of the ideal Airy profile. These results are then compared with the theoretical Cramer-Rao limit, establishing a benchmark to effectively compare optical systems, and to estimate the real scope of proposed telescope projects. The promising results obtained let us think in a further development of this idea, trying newmaterials more suitable for the specific application in optical astrometry. This simulated far-stellar field idea can be used to eventually design new in situ calibration methods for telescopes and other optical systems outside the astrometry field. N. Henríquez 1* , R. A. Méndez 2 , M. Gai 3 , A. Riva 3 , D. Dulic 4 1Departamento de Ingeniería Eléctrica, Universidad de Chile. 2Departamento de Astronomía, Universidad de Chile. 3Osservatorio Astrofisico di Torino, Istituto Nazionale di Astrofisica. 4Departamento de Física, Universidad de Chile. *Email: nestor.henriquez@ing.uchile.cl