| Optical synthetic aperture imaging technology is a new imaging technology that improves the resolution capability of optical telescope systems.By arranging several optical systems with smaller apertures in a certain form and imaging together,the technology can get the resolution similar to that of a single large aperture optical system,which is one of the effective means to achieve high-resolution imaging of optical system and reduce the manufacturing difficulty.Based on the requirements of high-resolution observation of air targets,this paper studies the multitelescope type synthetic aperture imaging system,and completes the system design and performance analysis based on the technical indicators.Firstly,the development status of the synthetic aperture imaging system is investigated,the differences between the two types of systems are analyzed,and the composition and working principle of the multi-telescope synthetic aperture imaging system are studied.The basic imaging theory is studied,a simplified model of the system is established,and the reasons for the system's increased resolution and the main characteristic indexes are simulated and analyzed.Secondly,based on the simplified model of the system,the reasons for the performance differences of the three typical pupil structures under different filling factors and sub-aperture blocking ratios are compared and analyzed from the perspectives of spectrum distribution characteristics and restored image quality.Genetic algorithm is used to optimize the multiaperture pupil structure based on the restored image quality,and the performance of the new pupil structure is compared and analyzed.The results show that the structure has higher imaging quality.Finally,in order to realize the identification of 30 km high-altitude aircraft and 2km flying objects,the overall parameters of the multi-telescope type synthetic aperture imaging system were determined,the design steps and schemes of the system were analyzed,and the reflective and reflexive synthetic aperture imaging were completed respectively.The design of the system.In order to meet the design requirements of system miniaturization,the reflective synthetic aperture imaging system uses an off-axis three-reflection structure integrated with the main three mirrors as the beam combining mirror,which not only simplifies the system structure,but also reduces the difficulty of installation and adjustment.In addition,the catadioptric synthetic aperture imaging system uses a catadioptric telephoto system and a transmission beam combiner system,and uses a mirror to fold the optical path to reduce the volume of the system.The performance of each subsystem and the whole are analyzed in detail,the effect of synthesis error is simulated,and the imaging effect of the system is simulated using the point spread function.In this paper,a five aperture catadioptric optical synthetic aperture imaging system is designed.Its structure is 350mm×350mm×620mm.The modulation transfer function of the system is continuous in the frequency domain,the maximum cut-off frequency in different directions of the spectrum is 162lp/mm,and the maximum difference of frequency response is about 0.05,which has good imaging performance and can meet the technical requirements of the project. |
