中国科学院机构知识库网格系统: 检索

Accurate focusing technology for the coronal images 会议论文 OAI收割
San Diego, CA, 2019-08-12
作者: Zhang XF(张雪飞); Liu Y(刘煜); Li XB(李小波); Song TF(宋腾飞); Zhao MY(赵明宇)

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收藏 | 浏览/下载：27/0 | 提交时间：2020/03/02

Image focusing Gradient algorithm Coronagraph Occulter

Polarization imaging of space target based on bicubic interpolation 期刊论文 OAI收割
Guangxue Jingmi Gongcheng/Optics and Precision Engineering, 2019, 卷号: 27, 期号: 12, 页码: 2555-2563
作者: Y.Ma; C.-Z.Zhang; Y.Liu; Z.Zhang

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收藏 | 浏览/下载：40/0 | 提交时间：2020/08/24

Image enhancement,Focal plane arrays,Focusing,Image resolution,Imaging systems,Interpolation,Polarization,Signal sampling,Textures

收藏 | 浏览/下载：114/0 | 提交时间：2015/09/02

集成电路显微图像自动采集自动对焦预采集/采集曲面拟合图像配准 AutoIt3 Integrated Circuit Micro-Image Auto-acquisition Auto-focusing Pre-acquisition / acquisition Surface Fitting Image Registration AutoIt3

An auto-focus algorithm of fast search based on combining rough and fine adjustment (EI CONFERENCE) 会议论文 OAI收割
3rd international Conference on Manufacturing Science and Engineering, ICMSE 2012, March 27, 2012 - March 29, 2012, Xiamen, China
作者: Zhang S.; Zhang Y.

收藏 | 浏览/下载：32/0 | 提交时间：2013/03/25

A coarse and fine combined fast search and auto-focusing algorithm was suggested in this paper. This method can automatically search and find the focal plane by evaluating the image definition. The Krisch operator based edge energy function was used as the big-step coarse focusing and then the wavelet transform based image definition evaluation function which is sensitivity to the variation in image definition was used to realize the small-step fine focusing in a narrow range. The un-uniform sampling function of the focusing area selection used in this method greatly reduces the workload and the required time for the data processing. The experimental results indicate that this algorithm can satisfy the requirement of the optical measure equipment for the image focusing. (2012) Trans Tech Publications.

Study on spectrograph for ionosphere: A broadband imaging instrument prototype for far-ultraviolet (EI CONFERENCE) 会议论文 OAI收割
International Symposium on Photoelectronic Detection and Imaging 2011: Space Exploration Technologies and Applications, May 24, 2011 - May 26, 2011, Beijing, China
作者: Wang S.-R.; Lin G.-Y.; Yu L.

收藏 | 浏览/下载：39/0 | 提交时间：2013/03/25

Current research on space-based exploration for the ionosphere needs more advanced technologies. Because the spectral signals in the ionosphere distributing basically in the far-ultraviolet waveband are very weak. Usual spectrometer structures and detectors such as CCD can't receive enough information. Based on this principle of atmospheric sounding the imaging spectrometer prototype for ionosphere detection application was designed to solve the problem. This prototype consists of the telescope and the imaging spectrometer. The simple structure and small number of mirrors can help higher transmission efficiency be achieved and weak signals detection be implemented. The telescope is an off-axis parabolic mirror and the spectrometer is a modified Czerny-Turner spectral imaging system. Modified Czerny-Turner spectrometer contains a spherical mirror a fixed plane grating and a toroidal mirror. By adjusting the incident angle to the collimating mirror and using toroidal mirror coma and astigmatism were corrected well. We also optimize distances between the grating to the focusing mirror and the focusing mirror to the image plane to improve disadvantages of traditional Czerny-Turner structure. Designed results demonstrate that aberrations are substantially corrected and high image quality can be obtained in broad waveband. The photon counting Wedge-Strip-Anode detector with micro-channel planes as the receiving plane is accepted for the instrument prototype. The other photon counting 2-D detector responding well for weak light such as Cross-Delay line detector and MAMA detector can also be used for detection. The calibration and performances testing system is made of a vacuum system a deuterium lamp a monochrometer and the instrument prototype. Results obtained from the experiment show that the spectral resolution is 2.4 nm and the spatial resolution is 80 m. The other calibration experiments are running. The technology of the spectrometer prototype is important for the research and applications of ionosphere remote sensing. 2011 SPIE.

Realization of auto-focusing system for cameras based on TMS320F2812 DSP (EI CONFERENCE) 会议论文 OAI收割
2nd Annual Conference on Electrical and Control Engineering, ICECE 2011, September 16, 2011 - September 18, 2011, Yichang, China
作者: Zhang T.

收藏 | 浏览/下载：29/0 | 提交时间：2013/03/25

Focusing systems play an important role in a variety of optical measurements and detection instruments. In this paper several kinds of auto-focusing methods were described and the relevant focusing evaluation functions were introduced based on image processing methods. An auto-focusing system based on image processing was designed by using the TMS320F2812 digital signal processing chip as a platform. Moreover some problem and solutions about auto-focusing system was demonstrated. The system designed in this paper can find the good image plane in 10 steps (about 5 second) thus it can meet the requirements of practical applications. 2011 IEEE.

Far-field focusing of laser beam based on digital image processing techniques (EI CONFERENCE) 会议论文 OAI收割
Optoelectronic Imaging and Multimedia Technology, October 18, 2010 - October 20, 2010, Beijing, China
作者: Zhao S.; Tian Y.-Z.; Liu L.-S.; Guo J.; Zhang H.-Y.

收藏 | 浏览/下载：28/0 | 提交时间：2013/03/25

In order to lead the laser beam transmit in the atmosphere convergently an experiment of laser focus at the distance of 450m and 300m has been operated in the outdoor place. The actual manipulations are as follows: Firstly the laser was collimated by a beam expander then the near-parallel laser beam was transmitted with a Galileo telescope system and the distance between the concave lens and the convex lens can be tuned through a precise displacement platform so the focus of the system changed due to the tiny displacement of the concave lens. Secondly the average power of the laser spot can be measured using power meter the power is 47.67mW and the standard deviation is 0.67mW while the focal length is 450m. Thirdly the energy distribution was found through the laser beam analyzer. The spot images were saved using the beam analyzer then the saved image can be processed with Matlab software afterwards. The function named EDGE and Sobel operator was used in the pre-processing of the saved image then method of median filter was used in the course of image de-noising and 53H filter was adopted in the signal analysis. The diameter of laser spot was obtained by the method above the diameter is 5.56mm and the standard deviation is 0.24mm. The spot center excursion is 0.56mm it is 10.43% of the total diameter of the laser spot. At last the key factors of the energy dissipation in the focusing system can be summarized as follows: restriction of the diffraction limit attenuation in the atmosphere geometrical aberration of optical system and the diffraction limit and the geometrical aberration are significant in the three factors above so we can reduce the impact of the both factors during the design of optical system. The reliable referenced data of the system design can be acquired through the primary experiment research. 2010 SPIE.

Inspection focus technology of space tridimensional mapping camera based on astigmatic method (EI CONFERENCE) 会议论文 OAI收割
5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optoelectronic Materials and Devices for Detector, Imager, Display, and Energy Conversion Technology, April 26, 2010 - April 29, 2010, Dalian, China
作者: Wang Z.; Wang Z.; Zhang L.; Zhang L.

收藏 | 浏览/下载：29/0 | 提交时间：2013/03/25

The CCD plane of the space tridimensional mapping camera will be deviated from the focal plane(including the CCD plane deviated due to camera focal length changed) under the condition of space environment and vibration impact when satellite is launching image resolution ratio will be descended because defocusing. For tridimensional mapping camera principal point position and focal length variation of the camera affect positioning accuracy of ground target conventional solution is under the condition of vacuum and focusing range calibrate the position of CCD plane with code of photoelectric encoder when the camera defocusing in orbit the magnitude and direction of defocusing amount are obtained by photoelectric encoder then the focusing mechanism driven by step motor to compensate defocusing amount of the CCD plane. For tridimensional mapping camera under the condition of space environment and vibration impact when satellite is launching if the camera focal length changes above focusing method has been meaningless. Thus the measuring and focusing method was put forward based on astigmation a quadrant detector was adopted to measure the astigmation caused by the deviation of the CCD plane refer to calibrated relation between the CCD plane poison and the asrigmation the deviation vector of the CCD plane can be obtained. This method includes all factors caused deviation of the CCD plane experimental results show that the focusing resolution of mapping camera focusing mechanism based on astigmatic method can reach 0.25 m. 2010 Copyright SPIE - The International Society for Optical Engineering.

Modeling and analysis of dialyte-lens auto-focusing technology for theodolite (EI CONFERENCE) 会议论文 OAI收割
2008 International Conference on Optical Instruments and Technology: Optoelectronic Measurement Technology and Applications, November 16, 2008 - November 19, 2008, Beijing, China
Wu L.-T.; Qiao Y.-F.; Wu D.-K.; Cai S.

收藏 | 浏览/下载：29/0 | 提交时间：2013/03/25

In order to realize real-time auto-focusing for theodolite lens-apart method was designed with the corresponding math model built and analyzed. An Object beam splitted after the first image surface of the theodolite traveled through two dialyte lens and then was imaged on CCD. The distance between two spots when exactly focused was set as the calibration value and the relationship between defocus distance and spot offset was given. The influence of tracking center shift and divergence angle etc. on focusing accuracy was analyzed. Compared with the traditional focusing method this scheme has a higher accuracy faster calculation higher tolerance for environment temperature and a simpler construction. The experiment result exhibited a resolution higher than 0.056mm which shows a bright engineering application prospect for this method. 2009 SPIE.

Space camera focusing forecast based on RBF network (EI CONFERENCE) 会议论文 OAI收割
Computational Intelligence and Intelligent Systems: 4th International Symposium, ISICA 2009, Huangshi, China, October 23-25, 2009. Proceedings, Tiergartenstrasse 17, Heidelberg, D-69121, Germany
作者: Liu J.; Yu D.; Yu D.; Liu J.; Liu J.

收藏 | 浏览/下载：29/0 | 提交时间：2013/03/25

As circumstance temperature of space camera changes flex of structural components and distortion of optical components lead to change of focal length and image quality. Radial Basis Function (RBF) network is used to approximate the complex nonlinear relation between focalization quantity image quality temperature level and axial temperature difference of space camera. After the RBF Network is trained with thermo-optical experiment data temperature level and axial temperature difference could be input to the network to obtain colder value of best image position. In this way focusing forecast under different temperatures can be realized. Results of focusing forecast experiment validate this method. 2009 Springer-Verlag Berlin Heidelberg.