2011
2011
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Record 337 of
Title:The research of attack angle measurement of projectile with CCD vertical target system
Author(s):Xu, Wei(1,2); Wang, Miao(2)Source: Procedia Engineering Volume: 15 Issue: DOI: 10.1016/j.proeng.2011.08.886 Published: 2011Abstract:Based on the coordinate measurement principle of the CCD vertical target system, a new method is proposed to measure the attack angle of flying projectile. It mainly analyze the coordinate measurement accuracy of the system and derive the formula for measuring the attack angle; In practical test, the attack angle measurement accuracy was proved to meet the request. The experimental results show that the method is feasible, and the CCD vertical target system not only measure the coordinates of flying projectile but also obtain the attack angle simultaneously, so that expand a wider range of applications of CCD vertical target measurement system. ? 2011 Published by Elsevier Ltd.Accession Number: 20115214631596 -
Record 338 of
Title:Theoretic analysis on mutual injection phase-locking fiber laser array
Author(s):Zhou, Liang(1); Duan, Kailiang(1); Zhao, Wei(1)Source: Chinese Optics Letters Volume: 9 Issue: SUPPL. 1 DOI: 10.3788/COL201109.S10305 Published: June 2011Abstract:We report on a new technique of mutual injection phase-locking fiber-laser array. This technique uses a 45° beam splitter as coupling device. Injection phase-locking process of the fiber-laser array is simulated and analyzed. Results show that constant values of phase differences are related to initial phases. Reflectivity of the beam splitter and transmissivity of cavity reflectors should be properly optimized in order to make injection phase-locking easier. ? 2011 Chinese Optics Letters.Accession Number: 20113214224375 -
Record 339 of
Title:Optimizing design of real-time spatial moving target tracking system
Author(s):Liang, Dong Sheng(1,2); Liu, Zhao Hui(1); Liu, Wen(1)Source: Advanced Materials Research Volume: 328-330 Issue: DOI: 10.4028/www.scientific.net/AMR.328-330.2234 Published: 2011Abstract:Achieving the detection and tracking of moving targets has been widely applied in all fields of today's society. Because of the shortcomings of traditional video tracking system, this paper proposes a novel method for designing video processing system based on hardware design of FPGA and DSP, and moving target in video can be detected and tracked by this system. In this system, DSP as the core of the system, it mainly completes the processing algorithms of video and image data, FPGA as a coprocessor, responsible for the completion of the processing of external data and logic. The hardware structure, link configuration, program code and other aspects of system are optimized. Finally, through the experiment, the input frame rate of video is 40frames/s, and the image resolution is 512pixels × 512pixels, median 16bites quantitative image sequence, the system can complete the relevant real-time detection and tracking algorithm and extract targets position of image sequences correctly. The results show that the advantage is that this system has powerful operation speed, real time, high accuracy and stability. ? 2011 Trans Tech Publications.Accession Number: 20113914373335 -
Record 340 of
Title:Spatially resolved X-ray spectroscopy using a flat HOPG crystal
Author(s):Yuan, X.H.(1,5); Carroll, D.C.(1); Coury, M.(1); Gray, R.J.(1); Brenner, C.M.(1,2); Lin, X.X.(4); Li, Y.T.(4); Quinn, M.N.(1); Tresca, O.(1); Zielbauer, B.(3); Neely, D.(2); McKenna, P.(1)Source: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment Volume: 653 Issue: 1 DOI: 10.1016/j.nima.2010.12.147 Published: October 11, 2011Abstract:A novel design of a 1-D imaging X-ray spectrometer is implemented, using a high efficiency HOPG (highly oriented pyrolitic graphite) Bragg crystal and a double-entrance-slit. The double slit provides self-calibration of the imaging magnification. The spatial and spectral resolutions and dispersion are characterised both analytically and by ray tracing simulations. A key feature of this approach is that it enables the X-ray spectrum to be measured over different regions of the plasma source. The application of this instrument is demonstrated in high intensity laserfoil interaction experiments. ? 2010 Elsevier B.V.Accession Number: 20113914363022 -
Record 341 of
Title:Alignment of off-axis conic aspheric mirrors in stigmatic null test
Author(s):Chen, Qinfang(1,2); Li, Yingcai(1); Ma, Zhen(1,2); Li, Xuyang(1,2); Liang, Shitong(1,2)Source: Guangxue Xuebao/Acta Optica Sinica Volume: 31 Issue: 2 DOI: 10.3788/AOS201131.0222001 Published: February 2011Abstract:During interferometric testing, an accurate evaluation of the surface information is one of the key factors in realizing deterministic manufacturing of off-axis aspheric mirrors. The method used in the analysis of wavefront aberration due to centring error in optical system is valid for test piece misalignment in an interferometric setting as well. The mathematic model of error separation is developed. In experiment, the test result of an off-axis aspheric mirror after alignment is 0.037 λ (RMS, λ=0.6328 mu;m), the test efficiency is improved effectively.Accession Number: 20111413890987 -
Record 342 of
Title:Ytterbium doped all-fiber-path all-normal dispersion mode-locked laser based on semiconductor saturable mirror
Author(s):Lian, F.Q.(1,2,3); Fan, Zh.W.(1,3); Wang, X.F.(1); Huang, Y.T.(1); Huang, K.(1); Ma, Y.F.(1); Niu, G.(1); Li, X.H.(4); Yu, J.(1)Source: Laser Physics Volume: 21 Issue: 6 DOI: 10.1134/S1054660X11110181 Published: June 2011Abstract:In this paper, we describe a compact all-fiber-path picosecond pulse based on Ytterbium doped fiber oscillator. A home-made novel SESAM mounted on fiber is reported, by which stable mode locking is obtained. The SESAM possesses the low saturation flux 20 μJ/cm2 (versus prior low saturation flux 32 μJ/cm2), which effectively reduces the pump power threshold of mode locking. The fiber laser generates 15 ps pulse trains without a dispersive delay line or anomalous dispersion in the cavity. Mode locking pulse with 30 MHz basic repetition-rate was produced, with 10-30 mW scale average output power at 1064 nm. Through 60 h of uninterrupted laser operating, mode locking is steady as ever. ? Pleiades Publishing, Ltd. 2011.Accession Number: 20113314243889 -
Record 343 of
Title:Development and military application of fiber optic rotary joint
Author(s):Mi, Lei(1,2,3); Yao, Shengli(1,3); Sun, Chuandong(1); Sun, Bo(3); Zhang, Hongju(1,3)Source: Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering Volume: 40 Issue: 6 DOI: Published: June 2011Abstract:The fiber optic rotary joint has been widely used in the field of national denfence and industrial design. The function of fiber optic rotary joint is to communicate crucial data from rotating platform to stationary platform. The specific use, working principle and production methods of single-channel and multi-channel fiber optic rotary joint were described. And foreign fiber optic rotary joint developments and technical specifications were introduced. The insertion loss of a fiber optic rotary joint depended on the mechanical misalignments of the fiber collimator. A single mode single-channel fiber optic rotary joint whose insert loss was below 2 dB was designed. Comparative experiment of temperature impact for fiber optic rotary joint was carried out. Test results were better than that of the foreign products. The characteristics of fiber optic rotary joint were analyzed. Finally, the applications of fiber optic rotary joint in national denfence have been introduced.Accession Number: 20113114199270 -
Record 344 of
Title:Optical system design of a two-linear array stereoscopic mapping CCD camera
Author(s):Chang, Lingying(1,2); Zhao, Baochang(1); Yang, Jianfeng(1); Wen, Desheng(1)Source: Zhongguo Jiguang/Chinese Journal of Lasers Volume: 38 Issue: 8 DOI: 10.3788/CJL201138.0816001 Published: August 2011Abstract:In order to obtain the image of 7 m resolution with the Chang'E-2 CCD stereoscopic camera on the 100-km-altitude circular orbit, a two-linear array CCD camera stereoscopic mapping optical system is designed. The principle of two-linear array stereo mapping camera is described. According to the satellite requirements, the main parameters of the optical system are calculated detailedly. The focal length of the system is 144.4 mm, the view angle is 42'E-2 satellite CCD stereoscopic camera are obtained. The images are clear and rich of detail information, demonstrating the effectiveness of the optical system.Accession Number: 20113714332863 -
Record 345 of
Title:An adaptive OPD and dislocation prediction used characteristic of interference pattern for interference hyperspectral image compression
Author(s):Wen, Jia(1,2); Ma, Caiwen(2); Shui, Penglang(2)Source: Optics Communications Volume: 284 Issue: 20 DOI: 10.1016/j.optcom.2011.06.061 Published: September 15, 2011Abstract:According to the imaging principle and characteristic of LASIS (Large Aperture Static Interference Imaging Spectrometer), we discovered that the 3D (three dimensional) image sequences formed by different interference pattern frames, which were formed in the imaging process of LASIS Interference hyperspectral image, had much stronger correlation than the original interference hyperspectral image sequences, either in 2D (two dimensional) spatial domain or in the spectral domain. We put this characteristic into image compression and proposed an adaptive OPD (optical path difference) and dislocation prediction algorithm for interference hyperspectral image compression. Compared the new algorithm proposed in this paper with Dual-Direction Prediction [1] proposed in 2009, lots of experimental results showed that the prediction error entropy of the new algorithm was much smaller. In the prediction step of lifting wavelet transform, this characteristic would also reduce the entropy of coefficients in high frequency significantly, which would be more advantageous for quantification coding [2]. ? 2011 Elsevier B.V. All rights reserved.Accession Number: 20113314236919 -
Record 346 of
Title:Athermalization design of a dual field-of-view IR optical system
Author(s):Tan, Ting(1,2); Yang, Jianfeng(1); Zhou, Ke(1,2)Source: ICEOE 2011 - 2011 International Conference on Electronics and Optoelectronics, Proceedings Volume: 2 Issue: DOI: 10.1109/ICEOE.2011.6013180 Published: 2011Abstract:Infrared imaging optical system are often asked to have good imaging performance, especially while surrounding temperature varies in a large range. Because of infrared material's sensitivity to temperature, athermalization should be taken into account in its design process in order to meet different user's demand. In this study we undertake the design and construction of a dual field-of-view lenses optimized for use in the infrared waveband(3.5～5μm), of which the F/# is 2, and it offers a dual EFL of 200/400 mm. Analysis show the system has fine and steady imaging performance within the range of -40 ～60°C, and its MTF curves and spot diagrams show a good image quality , besides, its length and size are permitted, which is acceptable to a certain theodolite. ? 2011 IEEE.Accession Number: 20114014386298 -
Record 347 of
Title:The tempo-spatially modulated polarization atmosphere Michelson interferometer
Author(s):Zhang, Chun Min(1,2); Zhu, Hua Chun(1,2); Zhao, Baochang(3)Source: Optics Express Volume: 19 Issue: 10 DOI: 10.1364/OE.19.009626 Published: May 9, 2011Abstract:A space-based tempo-spatially modulated polarization atmosphere Michelson interferometer (TSMPAMI) is described. It uses the relative movement between the TSMPAMI and the measured target to change optical path difference. The acquisition method of interferogram is presented. The atmospheric temperatures and horizontal winds can be derived from the optical observations. The measurement errors of the winds and temperatures are discussed through simulations. In the presence of small-scale structures of the atmospheric fields, the errors are found to be significantly influenced by the mismatch of the scenes observed by the adjacent CCD sub-areas aligned along the orbiter's track during successive measurements due to the orbital velocity and the exposure time. For most realistic conditions of the orbit and atmosphere, however, the instrument is proven suitable for measuring the atmospheric parameters. ? 2011 Optical Society of America.Accession Number: 20112013982268 -
Record 348 of
Title:Optical system design of space fisheye camera
Author(s):Yan, Aqi(1,2); Yang, Jianfeng(1); Cao, Jianzhong(1); Zhu, Qing(1); Zhang, Zhi(1); Wu, Dengshan(1); Wang, Hao(1)Source: Guangxue Xuebao/Acta Optica Sinica Volume: 31 Issue: 10 DOI: 10.3788/AOS201131.1022004 Published: October 2011Abstract:Optical system of a space fisheye camera based on 1/3 inch (1 inch=25.4 mm) CCD is designed considering the space environment. The focal length of the fisheye optical system is 2.1 mm, the F number is 4, and the field of view is 210°. The required working temperature is between -40°C~+60°C. After careful studying the influence of space environment such as the space γ radiation and ultraviolet radiation, temperature change and vacuum on the optical system, the technique for keeping image quality in space environment is put forward. The fisheye lens can reach excellent imaging quality in such an austere environment, and provide important guarantee for information capture with extreme wide-angle view on the orbit.Accession Number: 20114914584037