Design and test verification of baffle for off-axis three-mirror space optical remote sensor
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摘要:遮光罩是空间光学遥感器的重要组成部分,是抑制空间光学遥感器杂散光的首要措施。遮光罩削弱杂散光效果的好坏直接影响到光学遥感器光学系统的成像品质。本文设计了一种满足离轴三反空间光学遥感器要求的大尺寸碳纤维/环氧复合材料遮光罩,并结合有限元分析、杂散光分析及力学试验、光学系统传递函数检测手段来验证该遮光罩是否满足航天使用要求。结果显示,各视场光学系统传递函数检测结果基本一致,均在0.2以上。表明该大尺寸遮光罩具备良好的结构的稳定性、可靠性,能够满足空间应用要求。Abstract:The baffle is an important component of the space optical remote sensor, which is the main way to weaken the stray light from the out-of-field radiation source, and the imaging quality of the space optical remote sensor is dependent on the baffle's performance. In this paper, a large size baffle layout will be designed to meet the off-axis Wetherell TMA optical system. The baffle is made of carbon fiber reinforced polymer(CFRP). The FEM analysis, stray light analysis, mechanical vibration test and optical system MTF test are used to verify the usage requirement in aerospace. Results show that the MTF of the optical remote sensor can reach up to 0.2 in each field of view. It is indicated that the baffle has stable structure and good reliability and can meet the requirements of space applications.
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Key words:
- space optical remote sensor/
- baffle/
- stability/
- FEM/
- stray light analysis
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表 1遮光罩前3阶自然频率及振型描述
Table 1.1st-3rdorder natural frequencies and vibration modes shapes
阶数 Fn(Hz) 振型描述 1 83.8 遮光罩上板前端居中位置沿Z轴向平动 2 159.5 遮光罩上板前端居中位置绕Y轴方向摆动 3 183.1 遮光罩上板前端居中位置绕X轴方向摆动 表 2遮光罩装配前后1 g重力作用下主支撑框架变形结果
Table 2.Supporting frame′s displacement results under 1 g gravity with and without baffle
重力方向 装配前/μm 装配后/μm 差值/μm X向 4.060 4.160 +0.1 Y向 4.544 4.565 +0.02 Z向 9.417 10.29 +0.87 表 3遮光罩动力学试验结果
Table 3.Mechanical vibration test results of the baffle
0.2g正弦扫频 谐振频率/Hz 正弦振动 0.2g正弦扫频 谐振频率/Hz 响应加速度/g 放大倍率 X向 189.22 5.73 1.64 188.73 Y向 176.45 6.16 1.76 175.99 Z向 479.21 3.66 1.04 479.21 表 4遮光罩力学试验前后传函检测数据
Table 4.MTF results before and after mechanical vibration test of baffle
测量状态 CCD1 CCD2 CCD3 CCD4 CCD5 CCD6 前 CTF 0.292 0.291 0.293 0.292 0.291 0.299 MTF 0.229 0.229 0.230 0.229 0.229 0.235 后 CTF 0.283 0.296 0.297 0.292 0.296 0.294 MTF 0.223 0.233 0.233 0.229 0.232 0.231 表 5遮光罩热真空试验前后传函检测数据
Table 5.MTF results before and after thermal vacuum test of baffle
测量状态 CCD1 CCD2 CCD3 CCD4 CCD5 CCD6 热真空前 CTF 0.298 0.302 0.295 0.293 0.297 0.295 MTF 0.235 0.237 0.232 0.230 0.233 0.231 热真空后 CTF 0.286 0.296 0.300 0.295 0.300 0.292 MTF 0.225 0.232 0.235 0.231 0.236 0.230 表 6遮光罩热光学传函检测数据
Table 6.MTF results in the thermal vacuum imaging test of baffle
测量状态 CCD1 CCD2 CCD3 CCD4 CCD5 CCD6 16 ℃ CTF 0.269 0.273 0.272 0.281 0.269 0.267 MTF 0.211 0.214 0.213 0.221 0.211 0.209 20 ℃ CTF 0.268 0.273 0.270 0.278 0.271 0.263 MTF 0.211 0.214 0.212 0.218 0.213 0.207 24 ℃ CTF 0.264 0.268 0.271 0.279 0.264 0.264 MTF 0.207 0.211 0.213 0.219 0.207 0.207 -
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