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Context: ASPIICS is a novel externally occulted solar coronagraph, which willbe launched onboard the PROBA-3 mission of the European Space Agency. Theexternal occulter will be placed on the first satellite approximately 150 mahead of the second satellite that will carry an optical instrument. During 6hours per orbit, the satellites will fly in a precise formation, constituting agiant externally occulted coronagraph. Large distance between the externalocculter and the primary objective will allow observations of the white-lightsolar corona starting from extremely low heights 1.1RSun. Aims: To analyzeinfluence of optical ghost images formed inside the telescope and develop analgorithm for their removal. Methods: We implement the optical layout ofASPIICS in Zemax and study the ghost behaviour in sequential and non-sequentialregimes. We identify sources of the ghost contributions and analyze theirgeometrical behaviour. Finally we develop a mathematical model and software tocalculate ghost images for any given input image. Results: We show that ghostlight can be important in the outer part of the field of view, where thecoronal signal is weak, since the energy of bright inner corona isredistributed to the outer corona. However the model allows to remove the ghostcontribution. Due to a large distance between the external occulter and theprimary objective, the primary objective does not produce a significant ghost.The use of the Lyot spot in ASPIICS is not necessary.

Modeling and removal of optical ghosts in the PROBA-3/ASPIICS externally occulted solar coronagraph