2013
2013
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Record 145 of
Title:Research on nonlinear error compensation method for interferometers based on tracker
Author(s):Zhao, Suwen(1,2); Zhu, Shaolan(1); Wen, Desheng(1)Source: Journal of Information and Computational Science Volume: 10 Issue: 11 DOI: 10.12733/jics20101899 Published: July 20, 2013Abstract:A dynamic nonlinear error compensation method for the interferometers is proposed to meet the design demands of the tracker. It makes the system reach high precise measurement when the target is moving with high speed. With the passive compensation method of the optical path, part of the errors are eliminated. Thus, the periods of the signals could be counted accurately. A dynamic compensation method is proposed for the displacement in less than one period. By tracking the peak values and valley values of the interference signals in one cycle, the zero offsets error and unequal amplitude error can be compensated; then the quadrature phase shift error could be compensated by tracking the intersection of the two compensated signals. By tracking the signals and renewing the compensation parameters, the signals even with random nonlinear errors can get high-precision subdivision. Experiment results show that the system can get nanometer accuracy even the target is moving at high velocity. The system has better adaptability to different environment and anti-jamming capability. ? 2013 Binary Information Press.Accession Number: 20133516678671 -
Record 146 of
Title:Color interpolation algorithm of CCD based on green components and signal correlation
Author(s):Liang, Xiaofen(1,2); Qiao, Weidong(1); Yang, Jianfeng(1); Xue, Bin(1); Qin, Jia(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 8907 Issue: DOI: 10.1117/12.2033293 Published: 2013Abstract:Signal CCD/CMOS sensors capture image information by covering the sensor surface with a color filter array(CFA). For each pixel, only one of three primary colors(red, green and blue) can pass through the color filter array(CFA). The other two missing color components are estimated by the values of the surrounding pixels. In Bayer array, the green components are half of the total pixels, but both red pixel and blue pixel components are quarter, so green components contain more information, which can be reference to color interpolation of red components and blue components. Based on this principle, in this paper, a simple and effective color interpolation algorithm based on green components and signal correlation for Bayer pattern images was proposed. The first step is to interpolate R, G and B components using the method-bilinear interpolation. The second step is to revise the results of bilinear interpolation by adding some green components on the results of bilinear interpolation. The calculation of the values to be added should consider the influence of correlation between the three channels. There are two major contributions in the paper. The first one is to demosaick G component more precisely. The second one is the spectral-spatial correlations between the three color channels is taken into consideration. At last, through MATLAB simulation experiments, experimental pictures and quantitative data for performance evaluation-Peak Signal to Noise Ratio(PSNR) were gotten. The results of simulation experiments show, compared with other color interpolation algorithms, the proposed algorithm performs well in both visual perception and PSNR measurement. And the proposed algorithm does not increase the complexity of calculation but ensures the real-time of system. Theory and experiments show the method is reasonable and has important engineering significance. ? 2013 Copyright SPIE.Accession Number: 20141317510169 -
Record 147 of
Title:Super-resolution image reconstruction algorithm via regularized sparse representation
Author(s):Zhu, Bo(1,2); Li, Hua(3); Gao, Wei(1); Song, Zong-Xi(1)Source: Guangdianzi Jiguang/Journal of Optoelectronics Laser Volume: 24 Issue: 10 DOI: Published: October 2013Abstract:In order to produce a higher resolution image from a low-resolution one, a machine learning super-resolution image reconstruction method via regularized sparse representation is presented. A convex variational model is proposed for image super-resolution with sparse representation regularization. We further introduce two adaptive regularization terms into the sparse representation framework to improve the processing effect. Firstly, the Graph Laplacian based image clustering model which takes the local manifold structure into account to a given patch is selected to regularize the image local structures. Secondly, the image nonlocal self-similarity is introduced as another regularization term, which improves the quality of reconstructed images. Therefore, the sparse representation of a low-resolution image patch can be applied with the high-resolution image patch dictionary to generate a high-resolution image patch, and then, the high-resolution image is obtained. Experimental results proved that the proposed algorithm outperforms some state-of-the-art super-resolution methods both in peak signal-to-noise ratio (PSNR) measure and visual quality.Accession Number: 20134616974398 -
Record 148 of
Title:Design of new wide-angle unobscured three-mirror optical system
Author(s):Pang, Zhihai(1,2); Fan, Xuewu(1); Zou, Gangyi(1); Zhao, Hui(1)Source: Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering Volume: 42 Issue: 9 DOI: Published: September 2013Abstract:For the disadvantage of conventional three mirrors system to achieve wide field of view, a new-style unobscured three -mirror optical system with wide field of view was designed based on the retrofocus -type objective configuration. One powerful retrofocus design approach was the combination with a reversed Galilean Telescope, the expression of initial configuration parameters was obtained and the unobscured style was carried out by decenter the field. A system with effective focal length of 100 mm, field of view of 20° × 20° and F-number of 5 was designed, the modulation transfer function value at spatial frequency of 50 lp/mm was over 0.6 and image qualities were excellent. Compared with traditional common three-mirror optical systems, the most prominent advantage of this new three-mirror system are that it can provide wide field of view and just use two aspheric mirrors and one spherical, so that the cost of this system will be reduced.Accession Number: 20134817040197 -
Record 149 of
Title:Improvement of Bayer-pattern demosaicking with dictionary learning algorithm
Author(s):Zhu, Bo(1,2); Wen, De-Sheng(1); Wang, Fei(3); Li, Hua(4); Song, Zong-Xi(1)Source: Dianzi Yu Xinxi Xuebao/Journal of Electronics and Information Technology Volume: 35 Issue: 4 DOI: 10.3724/SP.J.1146.2012.00947 Published: April 2013Abstract:Demosaicking is important for the quality of digital images in resource-constrained single chip devices. This paper presents an improved dictionary learning-based color demosaicking algorithm. Firstly, an initial interpolation is applied to the R , B channel by Local Directional Interpolation (LDI) and fused by analysis the joint distribution of the gradient. Gaussian Mixture Model (GMM)-based clustering is used to classify dictionary image into different classes. The Principal Component Analysis (PCA) is performed on these classes to choose the principal components for the dictionary construction. And then, dictionary learning is applied to obtain the interpolated G? and the lost R? and B? are interpolated by the help of the reconstructed G?, accordingly. Since R?, G? andB? of the given pixels are better represented, the whole image can be reconstructed accurately. Taking McMaster color image dataset as dictionary, standard image and image from DALSA CMOS camera are used for effect evaluation of the demosaicking algorithm. Experimental results prove that the proposed algorithm outperforms some state-of-the-art demosaicking methods both in PSNR measure and visual quality.Accession Number: 20132016322910 -
Record 150 of
Title:Misalignment induced aberration characteristic of TMA optical system
Author(s):Pang, Zhihai(1,2); Fan, Xuewu(1); Chen, Qinfang(1); Ma, Zhen(1)Source: Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering Volume: 42 Issue: 3 DOI: Published: March 2013Abstract:Based on the vector wavefront aberration theory, the misalignment induced aberration's characteristic of TMA optical system was analyses in this paper. It is shown that a misaligned TMA has three residual 3rd aberrations. The 3rd order spherical aberration that is constant over the field and the 3rd order coma is a constant in magnitude and orientation over the field. Moreover, the 3rd order astigmatism is field-asymmetric in orientation and increases linearly with the field, and the location zero for the field-asymmetric, field linear astigmatism always reside at the center of the field of view. It has been demonstrated that a TMA under assembly is only measured to have perfect performance on-axis which is not aligned in any significant way, so the measurements of multiple field points for the TMA are required in the process of alignment. Under condition of remove axial coma, if astigmatism is measured on-axis, which is caused by the primary mirror astigmatic figure error but not the misalignment.Accession Number: 20132616448354 -
Record 151 of
Title:Design of airborne dual channel ultraviolet-visible imaging spectrometer with large field of view, wide spectrum, and high resolution
Author(s):Hao, Ai-Hua(1,2,3); Hu, Bing-Liang(1); Bai, Jia-Guang(1); Li, Li-Bo(1,3); Yu, Tao(1,3); Li, Si-Yuan(1)Source: Guang Pu Xue Yu Guang Pu Fen Xi/Spectroscopy and Spectral Analysis Volume: 33 Issue: 12 DOI: 10.3964/j.issn.1000-0593(2013)12-3432-05 Published: December 2013Abstract:The ultraviolet-visible (UV-Vis 200~500 nm) imaging spectrometer is an important part of space remote sensing. Based on special requirements and practical application of the airborne UV-VIS spectrometer, a kind of scanning imaging spectrometer using area array CCD is proposed, which can meet the application requirements of large field of view, wide spectrum and high resolution. It overcomes low spatial resolution of traditional line array CCD scanning imaging spectrometer, and limited field of view of the pushbroom imaging spectrometer. In addition, dual channel was designed to reduce stray light. 400~500 nm band includes two order spectrum for 200~250 nm band, and variation of radiance from earth between the shorter wavelength (310 nm) is above three orders of magnitude. In the structure design of the system, the imaging spectrometer is composed of a two-mirror concentric telescope and two Czerny-Turner plane grating imaging spectrometers. The whole system doesn't use any additional optical elements in addition to spherical mirrors. The whole system has the advantage of simple structure, excellent performance, and very good feasibility. The modulation transfer function value of full spectrum and full field of view is above 0.6.Accession Number: 20140117158170 -
Record 152 of
Title:Theoretical research on time-space conversion method for measuring ultra-short electron pulse width
Author(s):Wu, Jianjun(1,2); Yuan, Ximing(1,2); Zhao, Baosheng(3); Tian, Jinshou(3); Li, Junke(1,2)Source: Qiangjiguang Yu Lizishu/High Power Laser and Particle Beams Volume: 25 Issue: 2 DOI: 10.3788/HPLPB20132502.0517 Published: February 2013Abstract:The transmission characteristics of ultra-short electron beams of the ultra-fast electron guns in scanning state were analysed, and the deflection distance of the ultra-short electron beams passing the deflection-scan system was calculated. The results indicate that the initial voltage must be within the range of 700-1400 V to counterbalance the effect of the negative scan slope voltage, ensuring that the electron beams will pass the deflection-scan system and finally hit the phosphor screen of 30 mm in diameter, and the cooperative function of the initial voltage and the negative scan slope voltage is one of the two premises of the scan experiment. The other premise is the synchronization of the electrical and the optical signals. Following the discussion of the great difficulty caused by the first promise, an experimental system that can adjust the optical delay more effectively in the scan experiment was designed, which can facilitate the synchronization of the negative scan slope voltage and the ultra-fast electron pulse.Accession Number: 20130615999573 -
Record 153 of
Title:A novel compensation fiber coil for eliminating Sagnac Effect in fiber optic current sensor
Author(s):Wang, Yingli(1); Kang, Menghua(1,2); Ren, Liyong(1); Ren, Kaili(1,2); Xu, Jintao(1,3); Shi, Nianbao(1,3)Source: Chinese Control Conference, CCC Volume: Issue: DOI: Published: October 18, 2013Abstract:In Sagnac interferometer fiber optics current sensor, errors from the residual linear birefringence and environmental temperature and vibration sensitity has severely influenced on accuracy of this sensor. Spun highly linearly birefringent fiber has intrinsic sensitivity to magnetic fields through the Faraday Effect which result in simplification of optical element. The absence of the quarter wave plate result in good temperature performance and reducing light loss for less splice points. In this manuscript, the spun highly linearly birefringent fiber was designed and the vibration insensitive Sagnac interferometer fiber optics current sensor (S-FOCS) scheme was set up. In this scheme, the compensation fiber coil was designed to compensate the error caused by Sagnac effect in sensing fiber coil. Therefore, it is vibration immunity Sagnac interferometer fiber optics current sensor. The theoretical modeling of the state of light polarization was built by Jones Matrix. The results demonstrated that this novel sensor have good performance of conductor position insensitivity, temperature stability and vibration immunity. ? 2013 TCCT, CAA.Accession Number: 20135217123256 -
Record 154 of
Title:Monomode optical planar and channel waveguides in Yb3+-doped silicate glasses formed by helium ion implantation
Author(s):Liu, Chun-Xiao(1,2); Cheng, Shu(3); Zhao, Jin-Hua(4); Li, Wei-Nan(2); Wei, Wei(2,5); Peng, Bo(2,5); Guo, Hai-Tao(2)Source: Optics and Laser Technology Volume: 52 Issue: DOI: 10.1016/j.optlastec.2013.03.017 Published: 2013Abstract:Optical planar and channel waveguides in Yb3+-doped silicate glasses are fabricated by triple-energy helium ion implantation at a total dose of 6.0×1016 ions/cm2. The dark mode spectroscopy of the planar waveguide was measured using a prism coupling arrangement. The near-field mode profiles of the planar and channel waveguide were obtained with an end-face coupling system. The refractive index profile was reconstructed by the intensity calculation method. The results indicate that a refractive index enhanced region as well as an optical barrier has been created after the beam process. After post-implantation treatment at 260 C for 1 h, the channel waveguides possessed a propagation loss of ～1.2 dB/cm. The acceptable guiding properties suggest that further waveguide lasers may be realized on the He-implanted Yb3+-doped silicate glass waveguides. ? 2013 Elsevier Ltd. All rights reserved.Accession Number: 20132016323538 -
Record 155 of
Title:Vibration immunity fiber optic current sensor employing a spun or twisted highly linear birefringence fiber
Author(s):Kang, Menghua(1,2); Wang, Yingli(1); Xu, Jintao(1,3); Ren, Kaili(1,2); Liu, Shangbo(1,3)Source: Chinese Control Conference, CCC Volume: Issue: DOI: Published: October 18, 2013Abstract:Fiber optic current sensors (FOCS) based on Faraday magneto-optical effect have plenty of privileges compared to the traditional current sensors. However, the residual linear birefringence and environmental vibration sensitive problem are the fatal drawback in Sagnac fiber optic current sensors. In this paper, a vibration immunity sensing loop with a function of passive fiber optic polarization control is proposed, which consist of a spun or twisted fiber with highly birefringence. A spun or twisted fiber possesses two crucial functions: Remove the residual linear birefringence and control polarization of light. It is used as a substitute for fiber-optic quarter wave plate, which is sensitive to temperature fluctuation. Use the special fiber to encircle a distinctive geometric configuration, eliminating the influence of vibration or the Sagnac effect undesired. It has been demonstrated that the novel fiber optic current sensor has high sensitivity, considerable wide dynamic range, resistance to electromagnetic interference, and immunity of vibration. ? 2013 TCCT, CAA.Accession Number: 20135217123255 -
Record 156 of
Title:Design and development of a static X-ray imaging system used on SG-III laser facility
Author(s):Yang, Pin(1); Yang, Zhenghua(1); Li, Jin(1); Dong, Jianjun(1); Cao, Zhurong(1); Yan, Yadong(2); Wang, Wei(2); Wei, Mingzhi(2); Liu, Shenye(1)Source: Qiangjiguang Yu Lizishu/High Power Laser and Particle Beams Volume: 25 Issue: 11 DOI: 10.3788/HPLPB20132511.2895 Published: 2013Abstract:According to the target chamber structure and shooting mode of SG-III laser facility, a static X-ray imaging system (SXI) has been successfully developed based on the principle of pin-hole imaging. This system uses the imitated target for off-line targeting, and can be adjusted on-line, with the regulation accuracy of 81 μm and 40 μm. The pinhole component and filter component can be changed automatically, which realizes fast online aiming and running in vacuum environment. The displacement and stress were calculated using the software ANSYS to ensure the reliability of this system. Laser targeting evaluation of the system equipped with X-ray CCD has been conducted on SG-III laser facility. The result shows that the system reaches the requirement of the SG-III laser facility.Accession Number: 20135217144920