福衛五號遙測酬載於軌道上的熱變形與光學表現分析

Optical Performance Analysis of On-Orbit FORMOSAT-5 Remote Sensing Instrument

陳晉瑋(Ching-Wei Chen) ； 何承恩(Cheng-En Ho) ； 楊美怡(Mei-Yi Yang) ； 陳嘉瑞(Chia-Ray Chen)

《航測及遙測學刊》 18卷1期 (2014/03) Pp. 39-50

https://doi.org/10.6574/JPRS.2014.18(1).4

摘要

福衛五號計劃是第一個由國家實驗研究院國家太空中心自主研發的太空計劃，其中包括完整的衛星系統工程與光學遙測酬載的設計與製造。本研究進行太空環境與光學遙測酬載的模型建立與分析，並指出光學遙測酬載的結構與鏡面熱變形會進一步影響其光學性能表現。亦進行了一些初步的熱學與光機分析，探討光學遙測酬載於軌道上的行為，諸如溫度分佈、熱變形與成像品質劣化之間的關係。由於軌道上不同位置的熱負荷，光學遙測酬載在不同的取像位置其光學表現也將不同。本文詳細研究與探討熱變形的來源及其對成像品質的影響。

關鍵字

光學遙測酬載 ； Cassegrain型式望遠鏡 ； Zernike多項式係數 ； 光學傳遞函數MTF ； 波前像差WFE

並列摘要

FORMOSAT-5 is the first space program that National Space Organization (NSPO) takes full responsibility for the complete satellite system engineering design including payloads. FORMOSAT-5 will operate in a sun synchronous orbit at 720-km altitude with 98.28-degree inclination angle. The optical Remote Sensing Instrument (RSI) is a multispectral imager which contains one panchromatic band with 2-m ground sampling distance (GSD) and four multispectral bands with 4-m GSD. A Cassegrain type of RSI with two reflective aspheric mirrors and spherical corrector lens is designed. The space thermal environment is one of the important factors that affect the image quality of a space optical RSI. TRASYS and SINDA model of RSI have been established for thermal analysis. Both hot and cold cases have been studied. Thermal induced instabilities are incorporated in optical models (e.g., OSLO) by use of Zernike polynomial coefficients to calculate the system MTF and WFE. It is investigated that thermal deformation of RSI structure and mirrors will impact the optical performance. The relationship among temperature distributions, thermal deformations and image degradation of on-orbit behaviors are discussed.

並列關鍵字

Remote Sensing Instrument (RSI) ； Cassegrain telescope ； Zernike polynomial