Design Of Large-aperture And Long-focal-length Scanning Imaging Optical Syetem

With the rapid development of the remote sensing technology and relative technology, high resolution has become the direction of the remote sensing. Amplifying the aperture of the optical system is the way to improve the resolution, recently the developed countries are study large-aperture long-focal-length optical system. This article aims at designing large-aperture long-focal-length optical system, then analyzes the image quality of the optical system and scanning system and tolerances the optical system. The specific contents of this article as followed:In this article, First analyzed the recent situation of the remote sensing technology development, compared several optical system models which space camera often use, analyzed the figuration of the system and their application characters, determined three-mirror-anastigmat scanning optical system. Designed a large aperture long focal length scanning optical system which has30m-focal-length,3m-aperture-diameter,1°x0.2°-field. Due to the recent development of our country’s optical manufacture,it is too hard to produce a3m-aperture-diameter mirror, we section the primary mirror,and analyze the influence of distance between the sub-mirrors on the whole system.The size of CCD detector is80mm×60mm, the size of the image plane is530mm×108mm. In comparison to the image plane, the size of the CCD detector is too small. Due to the cost of jointing CCDs is so high and jointing CCDs exists cracks, using a scanning mirror to achieve the time-sharing image performance. But the scanning will produce defocus and image plane rotation, so calculate the value of the defocus and image rotation. During the practical progress, CCD should adjust location according to the value of the defocus and image rotation to make sure the normal imagery.At last, tolerance the integrity-aperture optical system and section-aperture system. The analysis result shows that the tolerance of the large-aperture optical system is relatively strict and that of the section-aperture system is far more strict. Adopting section-aperture optical system needs to manufacture and assemble exacting.The conclusion of this paper can provide theory foundations to manufacture the large-aperture optical system and synthetic-aperture optical system for our country, and provide the reference of designing and producing the supporting and controlling figuration of the scanning system.