Frequency Extraction and Degraded Image Synthesis for Golay3 Type Optical Sparse-Aperture Systems

A Fizeau-typesparse-aperture imaging system made of a constellation of telescope-bearing satellites can potentially achieve extremely high resolution. But in such a system, the Modulation Transfer Function (MTF) usually contains a zero value. This means that the system fails to acquire a particular spatial frequency. To overcome this problem, we acquire multiple degraded images by repeatedly changing the sub-aperture configuration and then synthesize their spatial frequencies to create a single improved image. We first analyze the MTFs between each individual sub-aperture and the whole sparse aperture system. Then, we design new sub-aperture configurations that acquire more spatial frequency and use frequency-domain filters to extract the high-SNR part from each degraded image. Finally, we synthesize these frequencies before image reconstruction. Our results demonstrate that this method effectively improves the quality of the final synthesized image by obtaining as much spatial frequency information from all degraded images as possible.