Design Of Ground-based Large Aperture Ultra-high Resolution Polarization Telescope Optical System

In order to identify the types of artificial satellites,understand the intention of the target,carry out space early warning and information confrontation,it is necessary to observe the satellite load and orbit.At present,most of the domestic satellite observations adopt the ground-based photoelectric detection method,however,due to the low diffraction resolution of the ground-based optical system,which limits the imaging ability of the system to the detail information,and the influence of the poor contrast of the target in the deep space background,it is unable to realize the all-time observation.In this paper,the combination of super-resolution imaging technology and polarization imaging technology is applied to the ground-based photoelectric detection system,which can break through the diffraction limit,improve the imaging resolution and the contrast of the target in the deep space background,this method can improve the contrast of the target,make the details of the image more obvious,and achieve the purpose of ultra-high resolution and all-time observation.This paper aims at the above problems.Firstly,the research status of ground-based large aperture optical system,super-resolution imaging technology and polarization imaging technology at home and abroad are analyzed,and then the basic theory of super-resolution imaging and polarization imaging are deeply studied.Based on the imaging index of the ground-based optical system for the satellite,the design scheme is determined.A common aperture super-resolution and polarization optical system with F number of 10 and field of view of 0.052°is designed.The energy links and tolerances of each system are analyzed.The results show that the energy meets the imaging requirements,and the tolerance allocation meets the processing and assembly requirements.The super-resolution optical system is designed in 587±10nm band.The modulation transfer function of the optical system is close to the diffraction limit at 71lp/mm of Nyquist frequency.The imaging quality meets the design expectation.Aiming at the problem that aberration affects the super-resolution effect,a four zone phase pupil filter is designed to study the influence of Zernike wavefront aberrations on the super-resolution imaging performance and local field of view.Based on the research conclusion,the spherical aberration and defocusing residual of the designed optical system are optimized reasonably,and the super-resolution ratio is increased from 1.21 times to 1.31 times.At this time,there is still a large local field of view.The design band of polarization optical system is 480nm?680nm,and the modulation transfer function of the optical system is better than 0.37 at 71lp/mm of Nyquist frequency.The system uses micro polarization detector to receive information,and four Stokes vectors of the target can be obtained at the same time.Through fusion processing,the polarization image of the target can be obtained.Finally,the super-resolution and polarization imaging experiments are carried out by building an experimental platform.The experimental results show that the designed phase pupil filter can achieve 1.18 times of super-resolution.When a proper amount of defocus and spherical aberration are added,the super-resolution ratio increases from 1.18 times to 1.25 times,and the local field of view can meet the use requirements.At the same time,in the polarization imaging experiment,the target contrast is increased by about 12%,and in the fusion image,the target contrast is increased by about 6%.Therefore,the super-resolution imaging technology and polarization imaging technology are used in the ground-based photoelectric detection system to achieve the purpose of improving the resolution of the optical system and the contrast of the target,which verifies the feasibility of this scheme.