Speaker
Description
Studies of image formation in astronomical instruments are often conducted under the assumption that light polarization has no significant influence. When diffraction effects are considered, they are typically treated using scalar point spread functions. This contribution aims to address the general problem by highlighting the potential impact of polarization and assessing it for a specific instrument through the estimation of point spread functions for all four Stokes parameters. Using dedicated partial occulters and pinholes installed as calibration tools for the TuMag instrument (Del Toro Iniesta et al. 2025) aboard the Sunrise III mission (Korea-Lagg et al. 2025), we derive polarized point response functions by exploiting two mathematical properties. A new description of the response of an optical instrument under polarized illumination and a description of its determination in the laboratory are proposed. An application to the TuMag instrument is presented.