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Research of On-orbit MTF Measurement for the Satellite Sensors 会议论文
作者:  Xu Miaozhong;  Cong Ming;  Li Huijie
收藏  |  浏览/下载：3/0  |  提交时间：2019/12/05
Space camera dynamic image quality measurement and evaluation (EI CONFERENCE) 会议论文
3rd International Conference on Measuring Technology and Mechatronics Automation, ICMTMA 2011, January 6, 2011 - January 7, 2011, Shanghai, China
Su W.; Zhang X.
收藏  |  浏览/下载：14/0  |  提交时间：2013/03/25
Design of reimaging F/1.0 long-wavelength infrared optical system (EI CONFERENCE) 会议论文
International Symposium on Photoelectronic Detection and Imaging 2011: Advances in Infrared Imaging and Applications, May 24, 2011 - May 24, 2011, Beijing, China
Zhang X.; Liu B.; Jia H.-G.
收藏  |  浏览/下载：27/0  |  提交时间：2013/03/25
A reimaging F/1.0 long-wavelength infrared optical system is proposed. The design has a flexible opto-mechanical layout. The design process is as follows. Firstly  the catadioptric reimaging system consists of two reflecting mirrors and a relay lenses. Two reflecting mirrors make up of the first imaging system and are therefore free of chromatic aberrations  while low dispersion lenses were used in the reimaging system  so the optical system do not need achromatic design for a high image quality. Then  to correct high-order aberrations resulting from large relative aperture  more parameters need to be used with aspheric or diffractive surfaces due to modern optic technology development. Here  aspheric is selected for easily manufacture. Finally  the design is completed with the help of ZEMAX software. The effective focal length of the objective is 120mm and the field of view (FOV) is 4. The simulated final design shows adequate image quality and the modulation transfer function (MTF) is close to diffraction limit. The effect of the surrounding environmental temperature is analyzed using the concept of thermal defocusing  and the thermal compensation is discussed. 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).  
The application of diagnostic equipment in the Tokamak fusion reaction (EI CONFERENCE) 会议论文
2011 International Conference on Optical Instruments and Technology: Optical Systems and Modern Optoelectronic Instruments, November 6, 2011 - November 9, 2011, Beijing, China
Zhang B.-S.; Chang J.; Gong X.-Z.; Gan J.-F.; Feng S.-L.
收藏  |  浏览/下载：11/0  |  提交时间：2013/03/25
This paper introduces the infrared optical system in the Tokamak fusion reaction device. In this optical system  3.the relay group lenses. This paper describes the decrease of the modulation transfer function (MTF) when the temperature changes and how to compensate the decrease of the MTF in order to maintain the image quality in a high level. As a result  the traditional optical structure can't meet the requirements  2.the Cassegrain system  the image quality of this optical system can reach the requirements when the temperature changes. 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).  because the length of the infrared optical system in the Tokamak is very long. The design of optical system in the detection facility includes three parts:1.the combination of the concave aspheric mirror and flat mirror  
Design of stable image platform on airborne camera (EI CONFERENCE) 会议论文
2011 International Conference on Advanced Design and Manufacturing Engineering, ADME 2011, September 16, 2011 - September 18, 2011, Guangzhou, China
Qian Y.; Yang L.; Hu F.; Hong X.
收藏  |  浏览/下载：11/0  |  提交时间：2013/03/25
Modulation transfer function resulting from random vibration was analyzed. To conclude that the effect of angular displacement was the major factor. Allowable MTF degradation was represented  and 34dB reduction was achieved at frequency of 100HZ. With the help of MSC.ADAMS simulation software  and convert allowable MTF degradation into stable system design parameters  simulated curve proves correct for isolator  which can guide perfect design for stabilization system. Based on the spatial mechanism and translational principle of parallelogram  and the irrotational displacement mechanism was tested by optical method  an irrotational displacement isolator was developed. It can meet the requirements of irrotational displacement and damp. An instance was given  coupled angle is less than 8?  it can satisfy the demand of aerial imaging. (2011) Trans Tech Publications.  
New method to improve measurement accuracy of modulation transfer function 会议论文
5th international symposium on advanced optical manufacturing and testing technologies, 大连, 2010-04-26
作者:  Gao W(高伟)
收藏  |  浏览/下载：8/0  |  提交时间：2010/12/25
Optimization of sampled imaging system with baseband response squeeze model 会议论文
Proceedings of the SPIE - The International Society for Optical Engineering, Optical Design and Testing III, Beijing, China, INSPEC
Huaidong Yang; Kexin Chen; Xingyue Huang; Qingsheng He; Guofan Jin
收藏  |  浏览/下载：4/0
Design and image restoration research of a cubic-phase-plate system (EI CONFERENCE) 会议论文
5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Advanced Optical Manufacturing Technologies, April 26, 2010 - April 29, 2010, Dalian, China
Zhang X.; Zhang X.; Shi G.; Zhang J.; He F.
收藏  |  浏览/下载：18/0  |  提交时间：2013/03/25
Wave-front coding technology is a novel jointly optical and digital imaging technology which can greatly extend the depth of focus of optical systems. The image restoration process is an important part of wave-front coding technology. Using wave-front coding makes the modulation transfer function(MTF) values of the optical systems change little over a range of several times the depth of focus  which means the system MTF is quite insensitive to defocus  and there is no zero in the passband. So we can design a single filter for the restoration of images in different defocus positions. However  it's hard to avoid noise during image acquisition and transmission processes. These noises will be amplified in the image restoration  especially in the high frequency part when the MTF drop is relatively low. The restoration process significantly reduces the system signal to noise ratio this way. Aimed at the problem of noise amplification  a new algorithm was proposed which incorporated wavelet denoising into the iterative steps of Lucy-Richardson algorithm. Better restoration results were obtained through the new algorithm  effectively solving the noise amplification problem of original LR algorithm. Two sets of identical triplet imaging systems were designed  in one of which the cubic-phase-plate was added. Imaging experiments of the manufactured systems were carried  and the images of a traditional system and a wave-front coded system before and after decoding were compared. The results show that the designed wave-front coded system can extend the depth of focus by 40 times compared with the traditional system while maintaining the light flux and the image plane resolution. 2010 Copyright SPIE - The International Society for Optical Engineering.  
Modulation transfer function in seeker camera limits resulting from missile flutter caused by aerodynamic force (EI CONFERENCE) 会议论文
2010 2nd International Conference on Industrial Mechatronics and Automation, ICIMA 2010, May 30, 2010 - May 31, 2010, Wuhan, China
Ai X.; Zhang X.; Jiang Z.; Wei Q.; Jia H.
收藏  |  浏览/下载：24/0  |  提交时间：2013/03/25
The imaging quality of seeker in flight mode has been evaluated through analyzing the effects of missile flutter on optical modulation transfer function (MTF) of the optical system. Firstly the data of transverse vibration has been processed to eliminate the trend term caused by the trajectory  then obtained the displacement with two times trapezoidal integration. For the side rotation  the high frequency noise interference in the data has been filtered by using five-point moving average method. Took this model as the quivering rule between the object and the image  and then analyzed the effects of the transverse vibration and the side rotation on imaging quality through MTF. By calculation  the r.m.s value of the image motion caused by missile transverse vibration is 0.026mm  and the side rotation angle is 0.0044 . Through the establishment of two modulation transfer functions (MTF) of image random vibration and linear vibration  the results show that the image quality had declined  and the effect of transverse vibration on image quality is obvious. Through improving the rigidity of the missile and selection of small focal length optical system and shorten the time of exposure can improve the imaging quality of the seeker. 2010 IEEE.  
Modulation transfer function measurement of sampled imaging systems in field test (EI CONFERENCE) 会议论文
5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optical Test and Measurement Technology and Equipment, April 26, 2010 - April 29, 2010, Dalian, China
Yang L.; Sun Q.; Wang J.; Zhang J.
收藏  |  浏览/下载：15/0  |  提交时间：2013/03/25
A digital mirror device (DMD) based light projector was developed as the target generator in modulation transfer function (MTF) measurement. In order to overcome the sampling-scene phase effect in MTF measurement of sampled imaging systems  a method using random targets is introduced to yield a phase-averaged MTF. The main potential problem of implementing this method is the fact that the stationary assumption of the random targets may be vitiated in practical measurement  especially in field test due to the ill condition. We provide an efficient model-independent way of analyzing and isolating the spectral contents arising from these additional contributions to MTF measurement. Algorithms with adaptive parameter selection were also developed for spectral estimation of the test image in order to overcome the challenge brought by the size limit of the test matrices for one certain field of view derived from the isoplantic region. The MTF measurement of a CCD video imager is used to demonstrate the measurement technique and illustrate the benefits over other methods. In order to validate the results  comparisons have been made between MTF measurements of imager implemented using this method and bar target direct measurements. 2010 Copyright SPIE - The International Society for Optical Engineering.  

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