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Effect of gimbal point displacement on optical axis pointing precision in an image seeker (EI CONFERENCE) 会议论文
2011 International Conference on Electric Information and Control Engineering, ICEICE 2011, April 15, 2011 - April 17, 2011, Wuhan, China
Zhang X.; Jiang Z.; Wei Q.; Jia H.
收藏  |  浏览/下载:29/0  |  提交时间:2013/03/25
A concentric glass spherical dome was usually chosen as the transparent window mounted in front of the optical lens in an image seeker. However  optical ray had to change its direction when propagating through the dome due to refraction unless passing through the center of the dome  which demanded gimbal point coincide with the center of the dome exactly. In fact  gimbal point displacement could not be eliminating due to fabrication  assembly and vibration  therefore the optical axis pointing error generated. In this paper  the effect of gimbal point displacement on optical axis pointing precision in an image seeker was analyzed  and the theoretical expression of the optical axis pointing error was derived based on geometric optics  and the error dynamics was explored by numerical. Take a visible light image seeker as a case  the thickness of concentric glass spherical dome was 8mm and the inner radius was 72mm  and the optical axis pointing errors varying dynamically with the look angle and the gimbal point displacement were shown in graph. When the gimbal displacement was 0.11mm  the maximum optical axis pointing error was 0.054mrad that is equal to the instantaneous field of view (IFOV) corresponding to the camera system whose focal length was 120mm and pixel size was 6.5m. Furthermore  with the gimbal displacement increasing  the optical axis pointing error increased linearly. The analyzed results provided a theoretical basis for the displacement range  which had to be limited strictly in the gimbal design process. 2011 IEEE.  
Dome design and coupled thermal-mechanical analysis of supersonic missile (EI CONFERENCE) 会议论文
2009 International Conference on Optical Instruments and Technology, OIT 2009, October 19, 2009 - October 22, 2009, Shanghai, China
Xing-qiao A.; Qun W.; Hong-guang J.
收藏  |  浏览/下载:39/0  |  提交时间:2013/03/25
A review of high-speed flow pressure and aerodynamic heating effect on Supersonic missile's dome is given. The dome should have excellent properties in optical  mechanical and chemical characteristics. A design of dome on supersonic mode is described according to tactical guide line of a missile. The dome made of quartz which is about 8mm thick and 141mm in window diameter. To check up the reliability of the dome  a reasonable finite element model (FEM) of dome is established  and a thermal-mechanical Analysis to the dome by finite element software NASTRAN has carried on  through these can obtained the distribution of temperature field and stress field when the speed is 2.3Ma. The results indicated that the stress was concentrated in the joint of the dome end and the Missile Section  and the maximum stress was 16.4Mpa. The stress of other nodes was smaller than the allowable stress of quartz glass. Reference to the results of the analysis  a lightweight revision to the dome structural dimension and a new method of dome fixing have put forward  which can reduce the stress concentration. 2009 SPIE.  


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