Concentration error analysis of space-based thin-film reflectors

Among numerous space solar power systems, the concentrator systems is more favored due to the size of the battery array and the emission cost. Space concentrators generally consider using low-quality thin film structures, which, although lightweight, have large deformation errors. When studying the concentration characteristics, slope error is generally used to describe the error, but the surface error of thin film structures is generally measured by the root mean square value (RMS). We found that the deformation of thin film structures has characteristic dimensions, that is, the deformation within a certain size range shows monotonic changes. We can use the quotient of surface error and feature size instead of slope error for optical calculations. In addition, within a certain deviation range of light distribution, we can use a plane instead of a surface to simplify the model when modeling. Based on these theories, we conducted numerical examples to verify and obtained analysis results.