2011
2011
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Record 97 of
Title:Hadamard transform spectrometer mixed pixels' unmixing method
Author(s):Yan, Peng(1); Hu, Bing-Liang(1); Liu, Xue-Bin(1); Sun, Wei(1); Li, Li-Bo(1); Feng, Yu-Tao(1); Liu, Yong-Zheng(1)Source: Guang Pu Xue Yu Guang Pu Fen Xi/Spectroscopy and Spectral Analysis Volume: 31 Issue: 10 DOI: 10.3964/j.issn.1000-0593(2011)10-2870-04 Published: October 2011Abstract:Hadamard transform imaging spectrometer is a multi-channel digital transform spectrometer detection technology, this paper based on digital micromirror array device (DMD) of the Hadamard transform spectrometer working principle and instrument structure, obtained by the imaging sensor mixed pixel were analyzed, theory derived the solution of pixel aliasing hybrid method, simulation results show that the method is simple and effective to improve the accuracy of mixed pixel spectrum more than 10% recovery.Accession Number: 20114214445658 -
Record 98 of
Title:Biologically inspired features for scene classification in video surveillance
Author(s):Huang, Kaiqi(1); Tao, Dacheng(2); Yuan, Yuan(3); Li, Xuelong(4); Tan, Tieniu(1)Source: IEEE Transactions on Systems, Man, and Cybernetics, Part B: Cybernetics Volume: 41 Issue: 1 DOI: 10.1109/TSMCB.2009.2037923 Published: February 2011Abstract:Inspired by human visual cognition mechanism, this paper first presents a scene classification method based on an improved standard model feature. Compared with state-of-the-art efforts in scene classification, the newly proposed method is more robust, more selective, and of lower complexity. These advantages are demonstrated by two sets of experiments on both our own database and standard public ones. Furthermore, occlusion and disorder problems in scene classification in video surveillance are also first studied in this paper. ? 2010 IEEE.Accession Number: 20110613652027 -
Record 99 of
Title:Long focal length large-aperture switch-zoom system design
Author(s):Wang, Yan-Bin(1); Duan, Jing(1); Jin, Hu-Min(1); Jiang, Kai(1); Zhang, Heng-Jin(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 8194 Issue: DOI: 10.1117/12.900258J Published: 2011Abstract:Compared with continuous zoom system, switch-zoom system has many advantages, such as simple structure, perfect imaging quality and easy fixing. A set of long focal length large-aperture visible switch-zoom system is designed in this paper. The system is composed of two parts: the front R-C object lens and the back switch-zoom system. When the back system is reversed, 1500～3000mm switch-zoom can be realized. In order to match the front R-C object lens' exit pupil with the back switch-zoom lens' entrance pupil, the front R-C object lens is controlled to be telecentric and the back switch-zoom system is telecentric at both image and object. The back switch-zoom system's object NA at short focal position is controlled to be equal to the front R-C object lens' image NA. Thus, the two parts can match with each other properly and the whole long focal length large-aperture visible switch-zoom system is designed. When the spatial frequency is 50lp/mm, the MTF of the R-C system and the back switch-zoom system are reaching to the diffraction limit to ensure the MTF of the whole system at both long focal position and short focal position. The RMS at each focal position is less than 10um. From the first surface to image plane, the overall length is 1100mm. The designed result shows that this zoom system has the advantages of simple structure, high image quality and easy fixing. ? 2011 SPIE.Accession Number: 20113714325855 -
Record 100 of
Title:Optical design of ground scenery simulator
Author(s):Chang, Lingying(1); Zhao, Baochang(2); Yang, Jianfeng(2); Chen, Liwu(2); He, Yinghong(2)Source: Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering Volume: 40 Issue: 12 DOI: Published: December 2011Abstract:In order to realize rapid image quality of CCD stereo camera and imaging spectrometer, an optical system applied in ground scenery simulator was designed. First, the optical system scheme of ground scenery simulator was described. Then on the basis of instrument and system considerations, the optical design parameters were distributed reasonably. The capital optical parameters of the designed system were as follow: f' was 150 mm, 2ω was 10°, spatial resolution was 36 lp/mm and spectrum range was 0.48-0.96 μm. The design result shows that the optical system of ground scenery simulator has almost no effect on image quality of CCD stereo camera and imaging spectrometer. The MTF value of its Nyquist special frequency is almost the same with that of CCD stereo camera and imaging spectrometer. It provides a basis for judging the normal state of CCD stereo camera and imaging spectrometer scientifically.Accession Number: 20120714765566 -
Record 101 of
Title:An adaptive VQ algorithm used in interferential multi-spectral image
Author(s):Wen, Jia(1,2); Ma, Cai-Wen(1); Shui, Peng-Lang(1)Source: Guang Pu Xue Yu Guang Pu Fen Xi/Spectroscopy and Spectral Analysis Volume: 31 Issue: 4 DOI: 10.3964/j.issn.1000-0593(2011)04-1033-05 Published: April 2011Abstract:In the present paper, an adaptive LBG VQ algorithm is proposed based on the point to line model for the expansion of LBG VQ algorithm which was proposed in 2009, and using the algorithm proposed in this paper can achieve less error quantification, and can avoid the increase in bits of the larger index generated by the point to line expansion of LBG VQ algorithm. This new algorithm was used in lossless compression of interferential multi-spectral LASIS image, and experiment shows that the adaptive LBG VQ algorithm can remarkably improve the lossless compression performance of interferential multi-spectral image, and that if using these VQ algorithms above after Dual-Direction Prediction, the compression ratio generated by the point to line expansion of LBG VQ algorithm will be a little less than that generated by conventional LBG VQ algorithm, and the compression ratio generated by the algorithm proposed in this paper will be much larger than that generated by conventional LBG VQ algorithm.Accession Number: 20112013989959 -
Record 102 of
Title:Optimization of high reflectivity measurement by cavity ring-down technique
Author(s):Liu, Rong(1); Li, Xin(2); Hou, Honglu(1); Yang, Zhi(3); Bai, Jintao(4)Source: 2011 Symposium on Photonics and Optoelectronics, SOPO 2011 Volume: Issue: DOI: 10.1109/SOPO.2011.5780377 Published: 2011Abstract:The reflectivity of cavity mirror has a great influence on output power and conversion efficiency of laser. Based on pulsed cavity ring-down (CRD) technology, a single wavelength reflectivity measuring system is set up. Comparing the testing curves, the system, whose ring-down cavity is confocal cavity, could accurately determine the reflectivity of a mirror at the wavelength of 946nm. The average values of ring-down time are 1.5857μs and 0.7950μs respectively. The reflectivity of the concave cavity mirrors is to be 99.7900%, and that of the flat mirror to be 99.7910%, relative error achieves to 10-5. Then the influence of the reflective metrical precision is studied with cavity parameters optimization and cavity length misadjustment. It is suggested that logarithm transformation of oscilloscope should be applied to adjust the optical cavity for improving metrical precision. The results will supply an effective instruct for improving intra-cavity frequency-doubling blue laser performance. ? 2011 IEEE.Accession Number: 20112514082944 -
Record 103 of
Title:Compressed hyperspectral image sensing with joint sparsity reconstruction
Author(s):Liu, Haiying(1); Li, Yunsong(1); Zhang, Jing(1); Song, Juan(1); Lv, Pei(2)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 8157 Issue: DOI: 10.1117/12.895425 Published: 2011Abstract:Recent compressed sensing (CS) results show that it is possible to accurately reconstruct images from a small number of linear measurements via convex optimization techniques. In this paper, according to the correlation analysis of linear measurements for hyperspectral images, a joint sparsity reconstruction algorithm based on interband prediction and joint optimization is proposed. In the method, linear prediction is first applied to remove the correlations among successive spectral band measurement vectors. The obtained residual measurement vectors are then recovered using the proposed joint optimization based POCS (projections onto convex sets) algorithm with the steepest descent method. In addition, a pixel-guided stopping criterion is introduced to stop the iteration. Experimental results show that the proposed algorithm exhibits its superiority over other known CS reconstruction algorithms in the literature at the same measurement rates, while with a faster convergence speed. ? 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).Accession Number: 20114214429351 -
Record 104 of
Title:The research of space telescope CCD camera image resource simulative system
Author(s):Yang, Zuoting(1,2); Wang, Hongwei(1,2); Qiao, Weidong(1); Ruan, Ping(1)Source: ICEOE 2011 - 2011 International Conference on Electronics and Optoelectronics, Proceedings Volume: 3 Issue: DOI: 10.1109/ICEOE.2011.6013307 Published: 2011Abstract:The equipment that the payload electronic control box matches the satellite Charge-Coupled Device (CCD) camera must be rigorously tested before being put into use. The traditional testing process is to make it with the bulky CCD camera system docking and then to capture a certain image to analyze, this will cause a waste of time and material. In consideration for the above problems, a simulative CCD camera image resource system is proposed in this paper. The control signal of a simulative CCD camera image resource is usually implemented in the Field Programmable Gate Array (FPGA), thus increasing the complexity of the hardware language, and stability will fall and making post-adjustment is more trouble. This paper presents a system which is controlled based on the host computer software. It makes complex code integrate into the host computer and sets aside a adjust interface to the software in advance, achieving with the FPGA circuit board to send the picture generated by the system cycle together. Sending images, image display and serial communication are usually for a thread in the general simulative CCD camera image resource system, this will inevitably cause some problems that often appear in the process. However, the system utilizes a three-run thread synchronization mode which makes the system more flexible, very easy to adjust. Extensive tests show that the simulative CCD camera image resource system has been running with satisfactory results. So it can replace CCD camera to test the payload electrical control box, which is stable and reliable test for the project and provides a strong support. ? 2011 IEEE.Accession Number: 20114014386422 -
Record 105 of
Title:Design and wavefront sensing for the segmented Spherical Primary Optical Telescope
Author(s):Shengzhang, Kai(1,2); Fan, Xuewu(1); Li, Chuang(1); Liu, Kai(1,2)Source: Proceedings of 2011 International Conference on Electronic and Mechanical Engineering and Information Technology, EMEIT 2011 Volume: 7 Issue: DOI: 10.1109/EMEIT.2011.6023831 Published: 2011Abstract:On account of the tight requirement of the high-resolution, the Segmented Primary Optical Telescope (SPOT) becomes the mainstream. Obviously, the use of a strongly aspheric form creates several intractable problems in manufacturing and subsequent optical testing of aspheric off-axis segments having different forms, the task of controlling a large number of aspheric segments for on-orbit cophasing is formidable, so the prospect of assembling the primary mirror from small, low-cost identical spherical mirror segments is very attractive. This paper will discourse upon the demand of the SPOT and analyze the advantages of segmented spherical primary mirror relative to aspheric. Besides these, the author will design an optical systems under the properties (D=1200mm, MTF ≥ 0.6), the optical designs use a full steerable, quasi-Cassegrain telescope in which the primary mirror uses spherical surface, then we will demonstrate its performance and prove the practicality of Spherical Primary Optical Telescope. Ultimately, we will introduce a multistage wavefront sensing and control strategy briefly for Diffraction-limited phasing. ? 2011 IEEE.Accession Number: 20114014403824 -
Record 106 of
Title:Theoretical modeling and experimental verification for structural response of NOPD based on endochronic theory
Author(s):Wang, Wei(1); Li, Yu Yan(2)Source: Applied Mechanics and Materials Volume: 52-54 Issue: DOI: 10.4028/www.scientific.net/AMM.52-54.800 Published: 2011Abstract:Non-obstructive particle damping (NOPD) is a new composite damping technology based on traditional partical damping and impacting damping, and it has good vibration-reduced results. Through studying thermodynamics constraint condition for non-inverse variation of inner tissue structure of the material, the endochronic theory obtained variation regularity of inner variable, further gave out evolution path of specific non-inverse thermodynamics variable under specific condition, and thus the constitutive relationship of the material was obtained. Based on endochronic theory, an incremental form of the endochronic constitutive relationship of discrete particle was derived, and then penalty element was introduced to solve the connection problem between structure and discrete particle, lastly finite element dynamics equation of NOPD composite structure was constructed. Based on the model of NOPD composite structure, simulation and experiment for response of NOPD free beam were made. It indicated that applying endochronic theory to analyze the response of NOPD is rational, which supplied an effective method for engineering application of NOPD. ? Trans Tech Publications.Accession Number: 20111613925518 -
Record 107 of
Title:A practical method to extending dynamic range of CCD camera
Author(s):Chen, Zhi(1,2); Qiu, Yuehong(1); Wen, Yan(1); Jiang, Baotan(1); Gao, Bo(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 8194 Issue: DOI: 10.1117/12.900007 Published: 2011Abstract:CCD (Charge Coupled Device) is the most popular detector for camera to detect low levels of light for wavelengths from 300nm to 1100nm. Contemporary CCD has read noise level equivalent to a few electrons, and Well capacity over 100,000 electrons. In order to take full advantage of these characteristics, it needs the dynamic of ADC must exceed the dynamic of the CCD. That is the number of bits provided by the ADC must exceed 16 bits. While the high reliability and inexpensive 16-20 bit A/D converter is few. In this paper, we firstly analyze CCD noise and then present the principle to extend the dynamic of the CCD in signal processing chain using two low resolution ADC with different sensitivity. At last we present a concrete example of improving the resolution of the ADC is by tow parallel low resolution ADCS with developing software to suitably process the converted analog-to-digital signal to achieve the same effect as a higher resolution ADC. ? 2011 SPIE.Accession Number: 20113714325919 -
Record 108 of
Title:Econdary optical lens designed in the method of source-target mapping
Author(s):Wang, Guangzhen(1,2); Wang, Lili(1); Li, Lin(1); Wang, Doudou(1); Zhang, Yajun(3)Source: Applied Optics Volume: 50 Issue: 21 DOI: 10.1364/AO.50.004031 Published: July 20, 2011Abstract:A secondary optical lens was designed and investigated in three-dimensional (3D) space, which was far more accurate than a two-dimensional space in far-field lighting. The shape of the lens surface was from numerical solutions to a group of equations based on source-target mapping; calculating time was only 1:6 s. Neglecting absorption and scattering loss, the main results show that, for circular lighting, light efficiency can reach as high as 95%, and uniformity, which is the ratio of the minimum illuminance to average illuminance, is 92.2%. For rectangular lighting, light efficiency can reach 83.6% and uniformity can reach 66.7%. Performance of lenses under different parameters was studied to provide direct references for production and application. ? 2011 Optical Society of America.Accession Number: 20113014178467