2017
2017
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Record 109 of
Title:Design of Hyperspectral Polarimetic Imaging System Based on LCTF and LCVR
Author(s):Yang, Fan-Chao(1,2); Li, Yong(1); Hu, Bing-Liang(1); Kong, Liang(1); Wei, Ru-Yi(1); Li, Hong-Bo(1,2)Source: Guang Pu Xue Yu Guang Pu Fen Xi/Spectroscopy and Spectral Analysis Volume: 37 Issue: 8 DOI: 10.3964/j.issn.1000-0593(2017)08-2610-05 Published: August 1, 2017Abstract:A hyperspectral polarimetic imaging system was proposed based on LCTF and LCVR. The system could break the limit of incomplete polarization acquiring by the conventional single LCTF system and acquire the full Stokes parameters of targets. It used the 4 different groups of phase retardance of LCVRs to build a 4×4 inversion algorithm matrix to calculate the original full polarization information. After calibration of the Retardance-Voltage characters of two LCVRs, the inversion algorithm was verified by laser at 633nm. The measured errors of full Stokes parameters, corresponding calculated degree and angel of linear polarization were analyzed, and the inversion algorithm was proved work well. The results indicated that the hyperspectral polarimetric imaging system could provide reliable hyperspectral and polarization information for remote sensing. ? 2017, Peking University Press. All right reserved.Accession Number: 20174304289418 -
Record 110 of
Title:ADRC system of FSM for image motion compensation
Author(s):Wang, Kaidi(1,2); Su, Xiuqin(1); Li, Zhe(1); Wu, Shaobo(1,2)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 10256 Issue: DOI: 10.1117/12.2268727 Published: 2017Abstract:In order to increase the speed controlling accuracy of fast steering mirror (FSM) for image motion compensation and thus to increase the definition of picture taken by moving camera, active disturbance rejection control (ADRC) is designed. First, mathematical model of FSM driven by voice coil motor (VCM) is established. Next, ADRC algorithm and its simplified form in actual application are clarified. Finally, simulation research for controlled object is made. The result is compared to control effect of PID. Simulation curves demonstrate that the settling time of ADRC is 6 ms and the bandwidth of system attains 102.2 Hz, which are nearly the same as those of PID. When the error is very small, it can converge to zero at a faster rate if ADRC is used. When the same range disturbance is given to system, the relative error of ADRC reaches 0.050%, which is about 42% of that of PID. ? 2017 SPIE.Accession Number: 20171703607511 -
Record 111 of
Title:Graphene on meta-surface for superresolution optical imaging with a sub-10 nm resolution
Author(s):Cao, Shun(1,2); Wang, Taisheng(1); Sun, Qiang(1); Hu, Bingliang(3); Levy, Uriel(4); Yu, Weixing(3)Source: Optics Express Volume: 25 Issue: 13 DOI: 10.1364/OE.25.014494 Published: June 26, 2017Abstract:Nowadays, wide-field of view plasmonic structured illumination method (WFPSIM) has been extensively studied and experimentally demonstrated in biological researches. Normally, noble metal structures are used in traditional WFPSIM to support ultrahigh wave-vector of SPs and an imaging resolution enhancement of 3-4 folds can be achieved. To further improve the imaging resolution of WFPSIM, we hereby propose a widefield optical nanoimaging method based on a hybrid graphene on meta-surface structure (GMS) model. It is found that an ultra-high wave-vector of graphene SPs can be excited by a metallic nanoslits array with localized surface plasmon enhancement. As a result, a standing wave surface plasmons (SW-SPs) interference pattern with a period of 11 nm for a 980 nm incident wavelength can be obtained. The potential application of the GMS for wide-field of view super-resolution imaging is discussed followed by simulation results which show that an imaging resolution of sub-10 nm can be achieved. The demonstrated method paves a new route for wide field optical nanoimaging, with applications e.g. in biological research to study biological processes occurring in cell membrane. ? 2017 Optical Society of America.Accession Number: 20172603861820 -
Record 112 of
Title:Lightweight structure design for supporting plate of primary mirror
Author(s):Wang, Xiao(1,2); Wang, Wei(1); Liu, Bei(1,2); Qu, Yan Jun(1,2); Li, Xu Peng(1,2)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 10463 Issue: DOI: 10.1117/12.2285730 Published: 2017Abstract:A topological optimization design for the lightweight technology of supporting plate of the primary mirror is presented in this paper. The supporting plate of the primary mirror is topologically optimized under the condition of determined shape, loads and environment. And the optimal structure is obtained. The diameter of the primary mirror in this paper is 450mm, and the material is SiC1. It is better to select SiC/Al as the supporting material. Six points of axial relative displacement can be used as constraints in optimization2. Establishing the supporting plate model and setting up the model parameters. After analyzing the force of the main mirror on the supporting plate, the model is applied with force and constraints. Modal analysis and static analysis of supporting plates are calculated. The continuum structure topological optimization mathematical model is created with the variable-density method. The maximum deformation of the surface of supporting plate under the gravity of the mirror and the first model frequency are assigned to response variable, and the entire volume of supporting structure is converted to object function. The structures before and after optimization are analyzed using the finite element method. Results show that the optimized fundamental frequency increases 29.85Hz and has a less displacement compared with the traditional structure. ? 2017 SPIE.Accession Number: 20180304654530 -
Record 113 of
Title:Adaboost-based detection and segmentation of bioresorbable vascular scaffolds struts in IVOCT images
Author(s):Lu, Yifeng(1,2); Cao, Yihui(1,2,3); Jin, Qinhua(4); Chen, Yundai(4); Yin, Qinye(3); Li, Jianan(1); Zhu, Rui(1); Zhao, Wei(1)Source: Proceedings - International Conference on Image Processing, ICIP Volume: 2017-September Issue: DOI: 10.1109/ICIP.2017.8297120 Published: July 2, 2017Abstract:Bioresorbable Vascular Scaffolds (BVS) are the most promising type of stent in percutaneous coronary intervention. For accurate BVS struts apposition assessment, intravascular optical coherence tomography (IVOCT) is the state-of-the-art imaging modality. However, manual analysis for IVOCT frames is time consuming and labor intensive. In this paper, we propose an automatic method for BVS struts center and region detection based on Adaboost algorithm and Haar-like features. Then, dynamic programming algorithm is applied to segment the contour of BVS struts. Based on the segmentation results, the apposed or malapposed struts can be automatically distinguished. By comparing the manual and automatic detection and segmentation results, our method correctly detected and segmented 87.7% of 4029 BVS struts with 18.6% false positives. The average Dice's coefficient for the correctly detected struts was 0.78. In conclusion, the evaluation suggested that this method is accurate and robust for BVS struts detection and segmentation. ? 2017 IEEE.Accession Number: 20181605019737 -
Record 114 of
Title:Study on the Polarization Spectral Image Dehazing
Author(s):Xia, Pu(1,2); Liu, Xue-Bin(1)Source: Guang Pu Xue Yu Guang Pu Fen Xi/Spectroscopy and Spectral Analysis Volume: 37 Issue: 8 DOI: 10.3964/j.issn.1000-0593(2017)08-2331-08 Published: August 1, 2017Abstract:Air pollution has a serious effect on the quality of image, and image taking under hazy weather suffers from poor contrast and resolution. It is of great significance to use the polarimetric spectral information for image dehazing and the research of polarization dehazing for spectral data cube. The data used in this paper was pushbroomed under moderate hazy weather, and original Vis-NIR polarimetric data of 380~1 000 nm was captured, the original polarimetric images at 450, 550, 650, 750, 850 nm and the dehazed images were studied. The results of the research showed that wavelength had a significant effect on the difference of gray value between targets and background, and both the dynamic range of gray value and the smoothness of histogram were improved after the dehazing process. On average, the image contrast of the far-field targets increased by 5 times. The far-field targets at 450 nm had the lowest contrast, and the dehazing process increased the image contrast by 7.13 times which made the undetectable targets detectable. The far-field targets at 850 nm had the highest contrast, and the dehazing process increased the image contrast by 3.86 times. The dynamic range of histogram of the full image increased to 13.5% to 28.6% from 450 to 850 nm, the dynamic range of histogram of the near-field targets are increased to 33.3% to 44.0%. Based on the analyzation of the possible estimation error, two correction factors were proposed to revise the degree of polarization of the airlight and the intensity of the airlight from an object at an infinite distance, the regularity of the two factors were given to guide the image dehazing process under new conditions. The polarimetric information is obtained through the original data by the Stokes parameters, the dehazing process is based on the polarimetric difference between the air light scattered from the haze particles and the direct light reflected from the objects. The polarization spectral dehazing technique not only expands the application area of the imaging spectrometer, but also provides a new idea for image dehazing. ? 2017, Peking University Press. All right reserved.Accession Number: 20174304289370 -
Record 115 of
Title:Design of compact high zoom ratio infrared optical system
Author(s):Qu, Rui(1); Mei, Chao(1); Yang, Hongtao(1); Cao, Jianzhong(1); Zhao, Yan(2)Source: Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering Volume: 46 Issue: 11 DOI: 10.3788/IRLA201746.1104002 Published: November 25, 2017Abstract:In order to solve the problems in high zoom ratio lens design, a two-stage-of-series zoom lens model was proposed based on optics zoom theory. Therefore, differential zoom equations were deduced and solved to help the lens power assignments, also the cam curve optimization condition and method were proved. In this model, first stage zoom was achieved by the two-part-zoom front part, and the given movement pattern of the compensation lens and the second magnified lens determined the second stage zoom, by which the 100% cooled stop efficiency was assured. Based on this method, a 70x MWIR zoom lens under the requirements of F/4, focal length 6.5-455 mm, HFOV 0.92°-58.2°, work waveband 3.7-4.8 μm was designed, which only used two kinds of infrared materials, consisted of 10 lenses, total length 300 mm, had good image quality and tolerance character. ? 2017, Editorial Board of Journal of Infrared and Laser Engineering. All right reserved.Accession Number: 20175204570947 -
Record 116 of
Title:Review of Optical Polarimetric Dehazing Technique
Author(s):Liang, Jian(1,2); Ju, Haijuan(1,2); Zhang, Wenfei(1,2); Ren, Liyong(1); Qu, Enshi(1)Source: Guangxue Xuebao/Acta Optica Sinica Volume: 37 Issue: 4 DOI: 10.3788/AOS201737.0400001 Published: April 10, 2017Abstract:Optical polarimetric imaging technique is a novel kind of optical imaging technique. The unique information is obtained by detecting the polarization characteristic of light, which is unavailable by other imaging techniques. Therefore, this technique can effectively enhance the detecting dimensions. In recent years, the optical polarimetric imaging technique is proved useful in the fields of clear imaging through haze or some other turbid media. Later, the optical polarimetric dehazing methods are developed rapidly as an independent branch, and many achievements are obtained so far. The principles, realization approaches and methods, developments and status quo are fully introduced. ? 2017, Chinese Lasers Press. All right reserved.Accession Number: 20172003665153 -
Record 117 of
Title:Generation of carrier-envelope phase stabilized laser from solid plates and application in high-harmonic generation
Author(s):Liu, Yangyang(1); He, Peng(2); Zhao, Kun(1); Huang, Hangdong(2); Jiang, Yujiao(2); Huang, Pei(3); Teng, Hao(1); He, Xinkui(1); Fang, Shaobo(1); Hou, Xun(3); Wei, Zhiyi(1)Source: Optics InfoBase Conference Papers Volume: Part F43-CLEO_AT 2017 Issue: DOI: 10.1364/CLEO_AT.2017.AF1B.4 Published: 2017Abstract:We demonstrated carrier-envelope phase (CEP) stabilized pulse as short as 5.4fs by compressing the octave-spanning spectrum from solid-state plates. Continuous and discrete HHG were observed by using the laser pulse as driver with different CEP. ? 2017 OSA.Accession Number: 20172403762954 -
Record 118 of
Title:An adaptive multi-Threshold image segmentation algorithm based on object-oriented classification for high-resolution remote sensing images
Author(s):Kai, Yu(1,2); Jiahang, Liu(1); Lu, Zhuanli(1,2)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 10462 Issue: DOI: 10.1117/12.2285511 Published: 2017Abstract:The object-oriented segmentation is a critical process in the classification and recognition of high-resolution remote sensing images. Multi-Threshold segmentation methods have been widely used in multi-Target recognition and information extraction of high-resolution remote sensing images because they are simple, easy-To-implement, and has ideal segmentation effect. However, the determination of thresholds for existing multi-Threshold segmentation algorithms is still a problem, which limits to get the best effect of segmentation. To address this issue we propose a self-Adapted multithreshold segmentation method, based on region merging, toward segmenting remote sensing images. This method involves four steps: image preprocessing based on morphological filtering, improved watershed transformation to initiate primitive segments, optimal region merging, and self-Adapted multi-Threshold segmentation. The performance of the proposed algorithm is evaluated in QuickBird images and compared to the existing region merging method. The results reveal the proposed segmentation method outperforms the existing method, as indicated by its lower discrepancy measure. ? 2017 SPIE.Accession Number: 20180404671029 -
Record 119 of
Title:Lunar-edge based on-orbit modulation transfer function (MTF) measurement
Author(s):Cheng, Ying(1,2); Yi, Hongwei(1); Liu, Xinlong(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 10463 Issue: DOI: 10.1117/12.2285836 Published: 2017Abstract:Modulation transfer function (MTF) is an important parameter for image quality evaluation of on-orbit optical image systems. Various methods have been proposed to determine the MTF of an imaging system which are based on images containing point, pulse and edge features. In this paper, the edge of the moon can be used as a high contrast target to measure on-orbit MTF of image systems based on knife-edge methods. The proposed method is an extension of the ISO 12233 Slanted-edge Spatial Frequency Response test, except that the shape of the edge is a circular arc instead of a straight line. In order to get more accurate edge locations and then obtain a more authentic edge spread function (ESF), we choose circular fitting method based on least square to fit lunar edge in sub-pixel edge detection process. At last, simulation results show that the MTF value at Nyquist frequency calculated using our lunar edge method is reliable and accurate with error less than 2% comparing with theoretical MTF value. ? 2017 SPIE.Accession Number: 20180304654536 -
Record 120 of
Title:Research on segmented mirror position error of optical system based on ZEMAX
Author(s):Wang, Chenchen(1,2); Zou, Gangyi(1,2); Li, Ruichang(1,2); Cui, Jian(3); Fan, Xuewu(1)Source: Optik Volume: 137 Issue: DOI: 10.1016/j.ijleo.2017.02.082 Published: May 1, 2017Abstract:We have modeled a segmented mirror optical system by software ZEMAX, and analyzed influence of segmented mirror's position error to the optical system imaging for the first time to author's best knowledge. The primary mirror is composed of 18 segmented mirrors. By adjusting each one's position error of six freedoms, we get six relationship curves between position error and the optical system's image quality. The relationship curves show that some have different wave-front error RMS values when segmented mirrors have same position errors. The middle mirrors are sensitive to the movement along X axis direction, and the outer ones are sensitive to the movement along Y axis direction. The middle ones and outer ones are all sensitive to the tilt error, especially tilt along X, Y axis. ? 2017 Elsevier GmbHAccession Number: 20171003422792