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Fabrication technique of large-scale lightweight SiC space mirror (EI CONFERENCE) 会议论文
3rd International Symposium on Advanced Optical Manufacturing and Testing Technologies, AOMATT 2007: Large Mirrors and Telescopes, July 8, 2007 - July 12, 2007, Chengdu, China
Zhang G.; Zhao R.; Zhao W.
收藏  |  浏览/下载：13/0  |  提交时间：2013/03/25
Silicon carbide (SiC) is a new type candidate material for large-scale lightweight space mirror. Its low thermal distortion  high stiffness  high optical quality  and its dimensional stability are better than other traditional optical substrate materials such as ULE  Zerodure  Beryllium (Be) and so on. In this paper  the lightweight silicon carbide space mirror blank was fabricated by reaction sintering. As a space born mirror material  silicon carbide must be an optical grade ceramic. So we prepared the silicon carbide green body with gel-casting method. Then some carbon materials were supplemented into the green body which will bring reaction-sintering with silicon in a vacuum furnace during 1500-1600C  ultimately the reaction bonded silicon carbide was made. The diameter of SiC space mirror blank we have made is 680mm. If expanding the size of the vacuum furnace  bigger mirror blank can be obtained. The test results show that the mechanical and thermal properties of RB-SiC are excellent with bending strength of 350MPa  fracture toughness of 4.1 MPa·m1/2 and coefficient of thermal expansion(CET) of 2.6710-6/K. The surface roughness(RMS) could be better than 3nm.  
Study on technology of orientation and north-finding based on fiber optic gyroscope (EI CONFERENCE) 会议论文
2007 IEEE International Conference on Mechatronics and Automation, ICMA 2007, August 5, 2007 - August 8, 2007, Harbin, China
Zhang Z.; Sun J.; Wu K.
收藏  |  浏览/下载：12/0  |  提交时间：2013/03/25
Research on 10.6 m laser beam monitoring in CO2 laser processing system (EI CONFERENCE) 会议论文
Infrared Materials, Devices, and Applications, November 12, 2007 - November 15, 2007, Beijing, China
Shi Y.; Gao Y.; Deng W.; Shao S.
收藏  |  浏览/下载：19/0  |  提交时间：2013/03/25
It is a key point of CO2 laser beam monitoring in the CO 2 laser processing system to achieve alignment between CO2 laser and PL (pointing and launching) system. By monitoring the angle offset of CO2 laser beam  the compensation can be gotten witch is given to fast-steering mirror to rectify the direction of laser beam. But the normal photoelectric detector can not get the laser signal because of CO2 laser's high energy and long wavelength. Its wavelength is 10.6m and its power can reach kW level. Consequently  it is difficult to detect the high-energy 10.6m laser beam directly. So  we monitored the output mirror of laser resonator superseded the laser beam  indirectly. The laser beam monitoring system could be designed based on CCD laser auto-collimation angular measurement principle and image processing method. In this paper  application of CCD laser auto-collimation angular measurement principle and image processing method for CO2 laser beam monitoring system is introduced particularly  After design  fabrication and alignment  the monitoring system can be used for experimental study that including angular measurement accuracy and angle offset measurement of CO2 laser beam. Angle offset range and angle variation rule of CO2 laser beam is also can be acquired for further research.  
Super-resolved imaging system with oversampling technology (EI CONFERENCE) 会议论文
3rd International Symposium on Advanced Optical Manufacturing and Testing Technologies, AOMATT 2007: Advanced Optical Manufacturing Technologies, July 8, 2007 - July 12, 2007, Chengdu, China
Zhang X.; Liu Y.; Zhang J.-P.; Wang L.-J.
收藏  |  浏览/下载：20/0  |  提交时间：2013/03/25
It has been a significant issue in the imaging filed to provide the highest possible resolution of an electro-optical imaging system(E-O imaging system). CCD arrays are inherently undersampled and spatial frequency above Nyquist frequency is distorted so as to create ambiguity and Moire patterns for targets imaged by E-O system.. As to this drawback  a system-design project is introduced and discussed in the paper. It's well known that many image quality metrics are linked to MTF. However  CCDs don't satisfy MTF condition  namely  the shift-invariant property  so MTF synthesis can't appraise the whole system simply by the MTF product of the few sub-system ones in E-O imaging system. Then it is depicted how to solve this problem in the following. Finally the analyses and comparisons of the imaging performance parameters with and without super-resolved technologies are shown.  
Design of high-resolution fourier transform lens (EI CONFERENCE) 会议论文
3rd International Symposium on Advanced Optical Manufacturing and Testing Technologies, AOMATT 2007: Advanced Optical Manufacturing Technologies, July 8, 2007 - July 12, 2007, Chengdu, China
Zhang L.; Zhong X.; Jin G.
收藏  |  浏览/下载：14/0  |  提交时间：2013/03/25
With the development of optical information processing  high-resolution Fourier transform lens has often been used in holographic data storage system  spatial filtering and observation of particles. This paper studies the optical design method of high-resolution Fourier transform optical lenses system  which could be used in particles observation and holographic data storage system. According to Fourier transform relation between object and its frequency plane and the theory of geometrical optics  the system with working wavelength 532nm and resolution 3 m was designed based on ZEMAX. A multi-configuration method was adopted to optimize the system's lenses. In the optical system  a diaphragm was placed at the system's spectrum plane and the system demanded a low vacuum to cut down the influences of atmosphere and other particles. The result of finite element analysis indicated that the influences of vacuum pumping to optics spacing and mirror surface shape very minor  and the imaging quality not being affected. This system has many advantages  such as simple structure  good image quality and a high resolution of 3 m. So it has a wide application prospect and can be used both in holographic data storage system and particles observation.  
Methods for integrated simulation of high-precision space optomechanical systems (EI CONFERENCE) 会议论文
3rd International Symposium on Advanced Optical Manufacturing and Testing Technologies, AOMATT 2007: Advanced Optical Manufacturing Technologies, July 8, 2007 - July 12, 2007, Chengdu, China
Dong W.; Guang J.; Hong-bo Y.
收藏  |  浏览/下载：16/0  |  提交时间：2013/03/25
Each disciplinary has its own modeling and analysis tools to solve its own specific field problems. In order to achieve integrated simulation of high precision space optical systems and predict optical performance respective to the mechanical and thermal loads  data must pass through different analysis tools. Simulation tools used in the thermal  structural and optical design process and the relationship among them were first depicted and the integrated simulation methods were described in detail. Zernike polynomial fitting methods and interpolating approaches were also demonstrated. Because of the orthogonality of Zernike polynomials  it was not probably used in some situations such as noncircular apertures and discrete data  and the coupling of Zernike polynomial coefficients and other methods were also introduced in the paper. The toolkit OMTIA (Optical  Mechanical and Thermal Integrated Analyzer) based on the methods was developed  which appears as an indispensable tool for engineering practice.  
Design and analysis of large spaceborne light-weighted primary mirror and its support system (EI CONFERENCE) 会议论文
3rd International Symposium on Advanced Optical Manufacturing and Testing Technologies, AOMATT 2007: Large Mirrors and Telescopes, July 8, 2007 - July 12, 2007, Chengdu, China
Yan Y.; Jin G.; Yang H.-B.
收藏  |  浏览/下载：14/0  |  提交时间：2013/03/25
With the development of the resolution of spaceborne remote sensor  the diameter of the primary mirror of spaceborne telescope becomes larger and larger. The distortion of primary mirror which is influenced by the mirror material  structure  self-weight  support system and temperature environment affects optical image quality finally. In this paper  an on-axis TMA high-resolution Cassegrain optical payload with a primary mirror whose diameter is 650mm was designed and the effects of the influence factors of the distortion acts on the on-axis TMA optical system primary mirror had been analyzed by means of Finite Element Analysis. During work  the technology of the primary mirror design had been summarized and general consideration of the primary mirror design technology also had been described at the same time. Considering the telescope manufacture and work station  a reasonable and optimal structure of the primary mirror sub-assembly is taken finally. In the end  the distortion of the primary mirror during its fabrication station and work station had been analyzed by integrated Finite Element Analysis Method. The results implicated the synthesis profile error (P-V value) for the primary mirror is less than /10 and all the indexes of the primary mirror satisfy the requirements of the optical system.  
Application of CMOS APS star tracker with large FOV in attitude and angular velocity determination (EI CONFERENCE) 会议论文
Advanced Sensor Systems and Applications III, November 12, 2007 - November 14, 2007, Beijing, China
Lu D.; Guang J.; Shaoju W.; Tao C.
收藏  |  浏览/下载：19/0  |  提交时间：2013/03/25
The paper deals with the spacecraft attitude determination problem using a new kind of star tracker with large FOV based on CMOS APS. Star tracker has been developed since 1970s and proved to be the most accurate sensor ever used in the spacecraft attitude determination systems. But the traditional CCD star tracker also has some disadvantages  such as small FOV  high power consumption  low sample rate and low working angular rate limit which prevent the use of CCD star tracker in attitude large angle maneuvering process. The new kind of star tracker based on CMOS APS has no such disadvantages and is more applicable on modern low-cost agile small satellites. Its higher sample rate and working angular rate limit over traditional CCD star tracker make it more adapt for spacecraft angular velocity determination. Because of the large FOV of the star tracker  the mathematical model of traditional CCD star tracker with a small FOV is not appropriate. So a new mathematical model was quoted to fit the star tracker with a large FOV. An alternative adaptive algorithm was also introduced in the paper. It can help the EKF algorithm work lacking of accurate covariance of the observation noise. An optimal estimation algorithm was used to estimate the angular velocity directly from the star tracker measurements. Mathematic simulation results indicate the CMOS APS star tracker can give accurate attitude information and estimated angular rate. The method can be used as the chief attitude determination system design of low-cost satellite without gyros  or be used as a backup strategy in the event of gyro failures to enhance the reliability of the attitude determination system.  
Study of high speed photography measuring instrument (EI CONFERENCE) 会议论文
27th International Congress on High-Speed Photography and Photonics, September 17, 2006 - September 22, 2006, Xi'an, China
Zhang Z.; Sun J.; Wu K.
收藏  |  浏览/下载：20/0  |  提交时间：2013/03/25
High speed photograph measuring instrument is mainly used to measure and track the exterior ballistics  which can measure the flying position of the missile in the initial phase and trajectory. A new high speed photograph measuring instrument is presented in this paper. High speed photography measuring system records the parameters of object real-time  and then acquires the flying position and trajectory data of the missile in the initial phase. The detection distance of high speed photography is more than 4.5km  and the least detection distance is 450m  under the condition of well-balanced angular velocity and angular acceleration  program pilot track error less than 5. This instrument also can measure and record the flying trail and trajectory parameters of plane  aero naval missile.  
Research on the support structure of the primary mirror of large-aperture telescope (EI CONFERENCE) 会议论文
3rd International Symposium on Advanced Optical Manufacturing and Testing Technologies, AOMATT 2007: Large Mirrors and Telescopes, July 8, 2007 - July 12, 2007, Chengdu, China
Yang W.; Jingxu Z.
收藏  |  浏览/下载：21/0  |  提交时间：2013/03/25
Large-aperture telescope can be used in surveying battlefield  researching landform  searching object  real-time monitoring  imaging  detecting and identifying spatial targets and so on. A large-aperture telescope for achieving high resolution power is designed to monitor spatial target and image in real time. Real-time monitoring plays an important role in military conflicts. The orbit parameter of object  quantity  geometrical shape parameter and so on can be obtained by detect spatial target. With the development of optical technology  people require larger aperture in optics-electronic (OE) system. By increasing optical aperture  the ability of collecting light and resolution power in the system can be enhanced. But the support structure of the primary mirror of large-aperture telescope will be a very difficult problem. With the increase of primary mirror aperture  the weight of the primary mirror will become larger than before. The root mean square (rms) of the primary mirror is affected by many factors  such as deadweight  deformation of heat  environment and so on. Due to the primary mirror of telescope is an important component of telescope system. By reducing the weight of primary mirror  precision of the system is ensured. During the designing phase  one can consider the supporting project of the primary mirror synthetically and analyze it roundly according to technical requirement of optical system and the effect factors. The final structural design can be reasonable. In an astronomical telescope  the surface of reflector is an important part for collecting dark radiation of celestial bodies. Its surface shape will have an effect on collecting efficiency of telescope radiant energy directly. So the rms must be very high. Optical system of large aperture  small wavelength and small focus can receive maximal light intensity. For ground-based optical astronomical telescope  the design proposed in the paper can satisfy the requirement of the possible minimum atmosphere seeing at astronomical observatory site and exert the use efficiency of the telescope adequately. So the accuracy of the traditional surface of reflector can assure that 90% of all the light energy can be focused on within the angle diameter range of the minimum atmosphere seeing  then 100% of light energy should be focused on the angle diameter range of minimum atmosphere seeing. Because the rms of mirror is very high  precise surface machining and accurate the support of mirror are very important tasks during designing and manufacturing the telescope. In the paper  various support techniques of a large-aperture telescope primary mirror are discussed and a 3.5 meter telescope system at the Starfire Optical Range (SOR) overviewed simply  which was operated by the Directed Energy Directorate of the Air Force Research Laboratory  Kirtland AFB  NM  USA from the ground-based O-E system for the observations of spatial target. We also analyze Theoretical elastic deformation of the Steward Observatory 2.3 meter mirror is analyzed.  

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