Study On The Two-mirror System With The Three Sub-mirror Sparse Aperture

In order to get better images of the distant targets, the request of the resolution for the telescopic system has been growing up rapidly, which normally needs large-aperture system. However, with the increase of the aperture of the traditional single large-aperture telescopic system, systems may suffer from the higher weight, the higher cost, the bigger size and other issues. For obtaining high resolution meanwhile breaking the limitation of aperture size, people have begun searching for new methods. Using the sparse aperture system instead of the traditional single large-aperture telescopic system is a popular research issue in recent years.The research background, significance and the research status around the world of the sparse aperture are introduced in detail in this paper. We preliminarily designed a full aperture R-C two-mirror telescopic system and replaced the primary mirror by three sub-mirrors. Based on that, we added two pieces of correction lens and optimized the optical system using ZEMAX optical design software so that there are little aberrations in the system. We simulated the imaging quality of the system when it had the assemble errors-piston error or tilt error. We put forward the relative ambiguity function, by which the quality of the image from the system with different assemble errors is described. Then we got images from the focus and defocus surface respectively from a system with some assemble errors. After analyzing the two pictures by the phase diversity method, we can calculate out the assemble errors and restore the original target image according to the testing outcomes. At last, the paper has summarized all the work and pointed out the next work that need to be done.