Research On Optical Design Schemes For Push-broom Imager

Push-broom scanning is a way of imaging widely used in the aerospace instruments. It has a simple structure and long integrating time which attributes to the possibility to realize high space resolution. Once the way of imaging was determined, optical system becomes an important factor in determining the instrument performance. This thesis explores the optical design schemes of push-broom imager, mainly completed the following work:(1) The specifications of optical systems are analyzed and demonstrated, basing on the requirement of aerospace instruments. Besides, the typical structures of the all reflective optical system and the refractive optical system are discussed, and after that, the design schemes are selected.(2) Under the same scope of specifications, two typical optical systems, Off-axis Three-mirror system and Double Gaussian system, are chose to design and finally multiple sets of results are obtained with F/4.8, F/2.4, and F/1.6. What’s more, taking "F/2.4, FOV=32° Double Gaussian system" and "F/2.4, FOV=32°×1° Off-axis Three-mirror system" for instance, the thesis made a overall analysis and summary of the two kinds of system from the tolerance analysis, thermal analysis, stray light analysis and alignment analysis. These results intuitively show the characteristics of the two kinds of systems. And these work provides a meaningful reference for selection of optical systems applied to push-broom imager.(3) Since aspheric surfaces are widely used in those designs, this thesis discusses the aspheric surface testing method in detail, and designs the aspheric surface testing scheme of a typical Off-axis Three-mirror system.