Kahil, F.Gandorfer, A.Hirzberger. J.Orozco Suárez, D.Albert, K.Albelo Jorge, N.Appourchaux, T.Alvarez Herrero, AlbertoBlanco Rodríguez, J.Germerott, DietmarGuerrero, LucasGutierrez-Marques, P.Sinjan, J.Calchetti, D.Kolleck, M.Solanki, S.K.Toro Iniesta, J.C. delVolkmer, ReinerWoch, J.Fiethe, B.Gómez Cama, José MaríaPérez-Grande, I.Sanchis Kilders, E.Balaguer Jiménez, M.Bellot Rubio, L.R.Carmona Flores, ManuelDeutsch, W.Fernandez-Rico, G.Fernandez-Medina, Ana B.García Parejo, P.Gasent Blesa, José L.Gizon, L.Grauf, B.Heerlein, K.Korpi-Lagg, A.Lange, T.López Jiménez, A.Maue, ThorstenMeller, R.Michalik, HaraldMoreno Vacas, A.Müller, R.Nakai, EijiSchmidt, WolfgangSchou, J.Schühle, U.Staub, J.Strecker, H.Torralbo, I.Valori, G.2025-04-242025-04-242022-01-010277-786Xhttps://hdl.handle.net/2445/220586The High Resolution Telescope (HRT) of the Polarimetric and Helioseismic Imager (SO/PHI) on-board the Solar Orbiter mission (SO) provides near diffraction limited observations of the solar surface. The HRT Refocus Mechanism (HRM) allows for acquiring calibration data in flight which are used in post processing on ground to estimate the image quality of SO/PHI-HRT data products and its dependence on the SO-Sun distance. Our aim is to characterise the wavefront aberrations in the optical path of SO/PHI-HRT and consequently the image quality in the focal plane of the telescope. We use calibration data taken during the Near Earth Commissionning Phase (NECP) and the second Remote Sensing Check-out Window (RSCW2) of Solar Orbiter’s Cruise Phase (CP). In particular, we apply a Phase Diversity (PD) analysis to estimate the low-order wavefront aberrations. The restoration with the retrieved Point Spread Function (PSF) from the PD analysis increases the RMS contrast of the solar granulation in the visible continuum from 4 % to 10−11%.11 p.application/pdfeng(c) Society of Photo-Optical Instrumentation Engineers (SPIE), 2022SolHeliosismologiaAstrofísicaSunHelioseismologyAstrophysicsinfo:eu-repo/semantics/article7500102025-04-24info:eu-repo/semantics/openAccess