Telescopes are one of the common types of satellite payloads. They are used both for Earth and astronomical observations. By using space telescopes it is possible to eliminate the negative effect of the atmosphere on image quality. Additionally, observations in some spectral ranges can be performed only from space due to absorption of certain wavelengths in the atmosphere. One such range is UV below 300 nm, which is of particular interest when it comes to the investigation of hot objects. Reflective telescopes are commonly used in this spectral range, although many classical designs are limited in their useful field of view to values below 1°. In this paper a hybrid refractive-diffractive telescope design working in a 200 nm – 300 nm spectral range with a field of view 10°×10° is proposed. Its performance is compared to purely refractive and reflective systems and significant improvement in the imaging quality of the system and decrease of its size is shown. The choice of the diffractive element type is explained. Parameters of the systems are based on the requirements for a proposed Polish mission UVSat which aims to enable long-term observations of a large number of stars exhibiting UV variance.

中文翻译：

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用于紫外观测的混合折射衍射望远镜的设计

望远镜是常见的卫星有效载荷类型之一。它们用于地球和天文观测。通过使用太空望远镜，可以消除大气对图像质量的负面影响。此外，由于大气中某些波长的吸收，某些光谱范围内的观测只能从太空进行。一个这样的范围是低于 300 nm 的紫外线，这在研究热物体时特别有趣。反射式望远镜通常用于该光谱范围，尽管许多经典设计的有用视场值被限制在 1° 以下。在本文中，提出了一种在 200 nm – 300 nm 光谱范围内工作的混合折射衍射望远镜设计，其视场为 10°×10°。将其性能与纯折射和反射系统进行比较，显示出系统成像质量的显着提高和尺寸的减小。解释了衍射元件类型的选择。该系统的参数基于拟议的波兰任务 UVSat 的要求，该任务旨在实现对大量表现出紫外线变化的恒星的长期观测。