PLATO camera ghosts: characterization of geometry and intensity from TVAC measurements of the flight models and the engineering model

The upcoming PLATO mission (Rauer et al., 2025) will, among others, discover and characterize thousands of exoplanets and is designed to reach the regime of Earth-like planets in the habitable zone of solar-type stars. Here we evaluate results of TVAC measurement campaigns performed in three different test houses in comparison to simulations for the characterization of optical ghosts in seven camera flight models and the engineering model. We investigated intensities and geometries of extended and point-like ghosts, emerging from parasitic reflections of incoming light in the optical system, as these can impact the scientific observations of PLATO. We found the ghost intensities to be well within the requirement specifications. The locations and sizes of the ghosts very well agree between the different cameras and with the simulations. Our findings prepare a camera-specific prediction of the ghost intensities and geometries for PLATO in flight.