Development of an ultra-lightweight scanning mirror for the optical imager of the second generation METEOSAT (MSG)
Development of an ultra-lightweight scanning mirror for the optical imager of the second generation METEOSAT (MSG)
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开发第二代METEOSAT（MSG）光学成像仪超轻型扫描镜
DOI：
10.1117/12.188099
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发表时间：
1994
期刊：
影响因子：
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通讯作者：
Ulrich Papenburg
中科院分区：
文献类型：
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作者：
B. Harnisch;A. Pradier;M. Deyerler;B. Kunkel;Ulrich Papenburg
一种名为C/SiC的新材料是当前超轻型扫描镜（ULSM） ESA/ESTEC技术开发合同的基础，该合同用于METEOSAT第二代（MSG）计划（参考文献{1}）。它由随机取向的碳纤维作为“绿体”组成，形成设计的形状，并在液相中渗透Si，形成富集SiC的表面层，并带有CVD生长的SiC光学抛光层。最后，在专用保护层下的反射涂层是银色的。对这面镜子的要求相当严格：在地球静止轨道上的7年寿命期间，它将永远暴露在卫星以100转/分旋转引起的离心力下。由于对指定的SEVIRI（旋转增强型可见红外成像仪）成像仪的高图像质量要求，仅扫描镜引起的MTF退化被定义为<EQ 3%，从而导致相当高的表面质量要求。主要贡献是自旋引起的反射镜尖端偏转，这被证明是设计的驱动因素。技术上最具挑战性的要求是开发一个具有800 X 500 mm2有效孔径和中央切口的扫描镜-该望远镜是Gregory概念-以承受严格的环境要求，其质量被指定为< 6公斤。ESA合同涵盖了一个基线概念，随后提出了一个单片C/SiC反射镜的设计，通过等静力安装与CFRP结构相匹配。在该技术项目结束时，将向欧空局提供一个经过全面测试的带有银和保护涂层的1:1比例镜子。由于该合同是一项技术合同，因此考虑到MSG扫描镜以外的应用，包括更高的光学表面质量，如(lambda) /30或曲面，以及可能更大直径的非球面反射镜。制造和光学工艺采用未在作者名单中列出的分包商，即SGL Carbon/Meitingen， FRG，用于硅渗透；Schunk Kohlenstofftechnik/GieBen， FRG的CVD SiC涂层；法国Ballainvilliers的REOSC Optique公司负责光学抛光，Jenoptik, Jena， FRG负责镀银和保护涂层。
A new material designated C/SiC is the basis for a current ultra-lightweight scan mirror (ULSM) ESA/ESTEC technology development contract for the METEOSAT Second Generation (MSG) Program (Ref. {1}). It consists of random- oriented carbon fibers as 'greenbody' which is shaped to the designed configuration, and is infiltrated in the liquid phase with Si resulting in a SiC enriched surface layer, with a CVD grown SiC optical polishing layer. The reflective coating finally is silver under a dedicated protection layer. The requirements for this mirror are rather stringent: during 7 years in a geostationary orbit of life it will permantly be exposed to centrifugal forces induced by the satellite spinning at 100 rpm. Due to high image quality requirements for the imager - designated SEVIRI (Spinning Enhanced Visible IR Imager) - the MTF degradation caused by the scan mirror alone are defined to <EQ 3%, resulting in rather high surface quality requirements. The main contribution is the spin induced mirror tip deflection which turned out to be the design driver. The technologically most challenging requirement is to develop a scan mirror with 800 X 500 mm2 effective aperture and a central cutout - the telescope is a Gregory concept - to withstand tight environmental requirements at a mass which was specified as < 6 kg. The ESA contract covers a baseline concept with the subsequently presented design of a monolithic C/SiC mirror, mated to a CFRP structure by isostatic mounts. At the end of this technology program, a fully tested 1:1 scale mirror with silver and protection coating will be rendered to ESA. Since this contract is a technology contract, applications beyond the MSG scan mirror are borne in mind, including higher optical surface qualities such as (lambda) /30 or curved surfaces, also aspheric mirrors of possibly even larger diameters. The manufacturing and optical process implement subcontractors which are not listed among the authors, i.e. SGL Carbon/Meitingen, FRG, for the Si infiltration; Schunk Kohlenstofftechnik/GieBen, FRG, for the CVD SiC coating; REOSC Optique, Ballainvilliers, France for the optical polishing, and Jenoptik, Jena, FRG, for the silver and protection coating.