Study On The Image Restoration Of Sparse Aperture Telescope

Optical Sparse Aperture Imaging Technology is a unconventional method to realize lightweight of space remote sensor and break the restriction on the resolution by the optical system aperture.However, because the special aperture configuration of sparse aperture system and misalignment of sub-aperture, the captured image is unable to be used directly. So Image restoration of Sparse Aperture Imaging System becomes an important step of Sparse Aperture Imaging Technology. In this paper, we carried out research on restoration of blurred image caused by misaligned Sparse Aperture Imaging System using phase diversity based on defocus, and the Phase Diversity computations is expedited to realize faster image restoration by using DSP.The main research contents in this paper are as follows:1. The theory of Sparse Aperture Imaging System image degradation is studied.The imaging theory of Sparse Aperture Imaging System, the performance indexes for evaluating the spase aperture configurations. The influence on imaging system's Point Spread Function (PSF), Modulation Transfer Function (MTF) and imaging quality by sparse aperture configuration, fill factor, sub-aperture misalignment as viewed from simulation experiment. On the basis of simplified sparse aperture imaging model, a sparse aperture imaging simulation software module, besides, the image quality evaluation methods for Sparse Aperture Imaging System are discussed. 2. The mathematical model and numerical methods are studied.The basic theory and mathematical model of Phase Diversity are analysed.Take a brief introduction to some numerical methods. Adopt adaptive genetic algorithm as numerical method, and improve the adaptive genetic algorithm based on prior knowledge.3. The simulation of sparse aperture system image restoration is studied.Firstly, the paper employ Wiener-Helstrom filter to perform the object restoration of Golay3 sparse aperture system degraded image. Secondly, use Phase Diversity to restore misalignment sparse aperture system degraded image. In addition, the image restoration in the Gaussian noise case is studied.4. Image restoration demonstration and experiment verification.Realize relative image restoration algorithm on the DSP target board based on DM642 chip. Optical sparse aperture imaging and image restoration testbed is set up to demonstrate and verify image restoration method. The experiment results indicate the adopted method is effective on sparse aperture imaging system image restoration.Finally, make a summary about research contents and point out the disadvantage of the research and the direction for subsequent research.