中国科学院机构知识库网格系统: 检索

Surface shape optimization for the space membrane reflector (EI CONFERENCE) 会议论文 OAI收割
2011 International Conference on Electronic and Mechanical Engineering and Information Technology, EMEIT 2011, August 12, 2011 - August 14, 2011, Harbin, China
作者: Zhang Y.; Zhang P.

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Space membrane reflector is very promised for optical quality application with the merits of ultra-lightweight and flexible. In order to improve the surface precision of membrane reflectors the formation and surface shape error of a membrane at uniform load are studied based on the henky-cambell equations of circular membrane. The ANSYS software is used to build an optimization model of membrane reflector surface shape in which the yield strength is the state variable the surface load on ten concentric annular regions of the mirror is the design variable and the minimum RMS between ideal surface and mirror surface is the target function. and the theoretical and experimental result show that RMS and PV of the optimized surfaces are reduced respectively than those before optimization. In a word this paper offers the theoretical and experimental basis of the polyimide membrane reflector. 2011 IEEE.

Evaluation of the operating range for ground-based infrared imaging tracking system (EI CONFERENCE) 会议论文 OAI收割
International Symposium on Photoelectronic Detection and Imaging 2011: Advances in Infrared Imaging and Applications, May 24, 2011 - May 24, 2011, Beijing, China
作者: Zhang Z.-D.

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Ground-based infrared imaging tracking system (GIITS) is of great importance for aerial target warning and guard. The operating range is one of the key performance specifications on the other which should be calculated calculate the radiation power received on the detector in order to analysis whether the output signal meets the detection requirements or not analyzed and studied during the whole GIITS design process. The operating range is mostly influenced by a few factors without considering the effect of the background radiation. By improving of the traditional method including atmospheric attenuation a new operating range calculation model of the GIITS was established based on two requirements. One is that the image size of observed target should meet the requirement of the processor signal extraction. The number of the pixel occupied by target image should be more than 9. The other is that the signal noise ratio (SNR) of the GIITS should not be less than 5 to meet the requirements of the target detection probability and spatial frequency. The SNR calculation equation in form of energy is deduced and the radiation characteristic of the observed target and background are analyzed. When evaluate the operating range of the GIITS using the new method the performance of GIITS and feature of target and background. This paper firstly makes analysis and summarization on the definite localizations of the traditional operating range equation of the GIITS. The localizations are mainly in two aspects. On one hand we should successively calculate two operating range values according to two requirements mentioned above and choose the minimum value as the analytic result. In the end the dispersion of the image and the effect of image dispersion are not considered in the traditional method an evaluation of operating range for fighter aircraft is accomplished as an example. The influence factors in every aspect on operating range were explored by the calculated result. The new operating range calculation model provides the theoretical basis for the design and applications as well as the comprehensive evaluation of a GIITS. 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).

Simulation and experiment of the static FTIR based on micro multi-step mirrors (EI CONFERENCE) 会议论文 OAI收割
International Symposium on Photoelectronic Detection and Imaging 2011: Sensor and Micromachined Optical Device Technologies, May 24, 2011 - May 26, 2011, Beijing, China
作者: Liang Z.-Z.; Zhang J.; Zhang J.; Zhang J.; Zhu W.-B.

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In recent years Fourier transform spectrometer (FTS) with small size and low mass is required in many applications with growing need for real-time and small platform spectral detection. In this paper a micro Fourier transform infrared spectrometer (FTIR) based on spatial modulation mode was designed. This spectrometer has the advantages of high stability and simplified configuration. It also promises optical path differences (OPD) with high precision as MOEMS technology is used in manufacturing the key components. The simulation and the experiments with regard to this FTIR configuration have been done. Firstly the diffraction effect of the micro multi-step mirrors (MMSMs) is studied. We discuss the influence to the reversed spectrum by different mirror widths and different diffraction distances. Secondly we simulate and analyze the influence of the source solid angle to the spectral resolution. Thirdly we set up the theoretical model of the collimation error which is mainly from the defocus of the optical system and analyze the result caused by the collimation error. Fourthly a new discrete Fourier transform arithmetic using least-squares cosines progression (LSCP) is proposed which can reconstruct the spectrum with nonuniform sampled signals. Finally the MMSMs are fabricated used the MOEMS technology and the structural parameters are tested. 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).

New phase measurement method for laser rangefinder (EI CONFERENCE) 会议论文 OAI收割
5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optical Test and Measurement Technology and Equipment, April 26, 2010 - April 29, 2010, Dalian, China
作者: Meng Z.; Meng Z.

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A new phase measurement method is designed and presented by using the technique of signal shifting phase and the technique of signal multiplication for laser rangefinder. The intensity of laser light is modulated by cosine circuit signal at the same time the cosine circuit signal is thansformed sine signal by the shifting phase technique. Two signals mentioned above are multiplied by received signal from the target respectively then being transmitted into signal processor after passing through low band filter respectively. The result of phase-shift between the received signal and sent signal is calculated by means of signal processor and time-counter with double frequency of modulation signal. The proposed system is composed of four units such as control and count unit emitting and receiving unit of laser light signal processing unit and result display unit. The two most advantages of proposed system over others are its ability of proper isolation which reduces crosstalk and its independency thermal drift. Theoretical calculations and experimental results have shown the accuracy better than 2 mm. 2010 Copyright SPIE - The International Society for Optical Engineering.

Underwater acoustic absorbing materials based on construction of locally resonant units and interpenetrating network 会议论文 OAI收割
17th International Congress on Sound and Vibration 2010, ICSV 2010, Cairo, Egypt, July 18, 2010 - July 22, 2010
作者: Wang YR(王育人); Jiang H(姜恒); Chen M(陈猛)

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Acoustic absorbing materials Acoustic absorption High mechanical strength Metal-polymer composites Resonant mode Theoretical result Wide frequency bands

Analysis of laser jamming to satellite-based detector (EI CONFERENCE) 会议论文 OAI收割
International Symposium on Photoelectronic Detection and Imaging 2009: Laser Sensing and Imaging, June 17, 2009 - June 19, 2009, Beijing, China
作者: Guo L.-H.; Guo R.-H.; Wang S.-W.

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The reconnaissance satellite communication satellite and navigation satellite used in the military applications have played more and more important role in the advanced technique wars and already become the significant support and aid system for military actions. With the development of all kinds of satellites anti-satellite laser weapons emerge as the times require. The experiments and analyses of laser disturbing CCD (charge coupled detector) in near ground have been studied by many research groups but their results are not suitable to the case that using laser disturbs the satellite-based detector. Because the distance between the satellite-based detector and the ground is very large it is difficult to damage it directly. However the optical receive system of satellite detector has large optical gain so laser disturbing satellite detector is possible. In order to determine its feasibility the theoretical analyses and experimental study are carried out in the paper. Firstly the influence factors of laser disturbing satellite detector are analyzed in detail which including laser power density on the surface of the detector after long distance transmission and laser power density threshold for disturbing etc. These factors are not only induced by the satellite orbit but dependence on the following parameters: laser average power in the ground laser beam quality tracing and aiming precision and atmospheric transmission. A calculation model is developed by considering all factors which then the power density entering into the detector can be calculated. Secondly the laser disturbing experiment is performed by using LD (laser diode) with the wavelength 808 nm disturbing CCD 5 kilometer away which the disturbing threshold value is obtained as 3.5510-4mW/cm2 that coincides with other researcher's results. Finally using the theoretical model the energy density of laser on the photosensitive surface of MSTI-3 satellite detector is estimated as about 100mW/cm2 which is largely exceed the disturbing threshold and therefore verify the feasibility of using this kind of laser disturbing the satellite-based detector. According to the results. using the similar laser power density absolutely saturate the requirements to laser disturbing satellite-based detector. If considering the peak power of pulsed laser even decrease laser average power it is also possible to damage the detector. This result will provide the reliable evidences to evaluate the effect of laser disturbing satellite-based detector. 2009 SPIE.

Heterogeneous architecture-based software reliability estimation: Case study (EI CONFERENCE) 会议论文 OAI收割
3rd International Conference on Convergence and Hybrid Information Technology, ICCIT 2008, November 11, 2008 - November 13, 2008, Busan, Korea, Republic of
Wei Y.; Shen X.-H.

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With growing system complication multiple structures are constructed in software instead of single architecture style. As a result the traditional architecture-based models that have considered only homogeneous software behaviors are not suitable to the complex system. In this paper a heterogeneous architecture-based model is presented. In order to verify the practicability we apply the model to estimate the system reliability of the astronautics payload communication and monitoring system (APCMS). Multiple structures are constructed in the system i.e. sequence parallel and fault-tolerance. The study results demonstrate that the model is accurate when compared to the actual reliability. Theoretical research must be applied on actual systems to understand their applicability and accuracy. 2008 IEEE.

Determination of optical constants of zirconia and silica thin films in UV to visible range (EI CONFERENCE) 会议论文 OAI收割
3rd International Symposium on Advanced Optical Manufacturing and Testing Technologies, AOMATT 2007: Advanced Optical Manufacturing Technologies, July 8, 2007 - July 12, 2007, Chengdu, China
作者: Liu L.; Yang H.; Liu L.

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A curve fitting method for determining the optical constants of some dielectric thin films is described with dispersion theory in the paper. A computer program based on Matlab is developed and optimized. The fitting errors are analyzed with theoretical data which gives very high accurate results. A program is applied to fitting the measured photometric spectra of ion sputtered zirconia and silica thin films in 200-850nm spectra range. The thickness is verified with the method of grazing x-ray diffraction. With the thickness known the optical constants of zirconia films near the absorption range are obtained with single-wavelength method. As a result quite good fitting results are obtained with high accuracy. Finally an ultraviolet (UV) high-pass optical filter is designed with optical constants extracted by this method. The transmission and reflection spectra of the filter are measured and compared to designed spectra. A good coherence was derived.

Support technique of ultra thin mirror in space optics (EI CONFERENCE) 会议论文 OAI收割
2nd International Symposium on Advanced Optical Manufacturing and Testing Technologies: Large Mirrors and Telescopes, November 2, 2005 - November 5, 2005, Xian, China
作者: Ren J.-Y.; Gao M.-H.

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With the development of space optical system the technique of ultra thin mirror come forth and is paid more attention because of less difficulty in machining low cost lightweight no disassembly during detecting and maintaining. The key technique takes advantage of deformation of ultra thin mirror as the influence of environment to adjust the surface figure. Its accuracy meets requirement. An analysis method is based on finite element analysis (FEA) and many items including the amount of support points the way of arrangement the optimum design of support component are studied. The finite element method was used to analyze the mirror and some different mirror support schemes. The principal aim of the mirror analysis is to get numbers of support points and the ways of the support. There are three schemes including 12-6-1 12-8-1 and 16-8-1 models. Deformation of deadweight is calculated under the three conditions. The way of 16-8-1 is more suitable than the designs of other two. The support subassembly is amended to meet with the mirror surface RMS in the range of 30m. Deformation of the mirror with support structure has been calculated. The result is 16.52nm lower than a quarter of the wavelength which indicates the feasibility of the support scheme applied to mirror. Theoretical result for the best way of support is presented. The result of analysis shows that requirement surface figure could be met through adjusting support points. It predicts feasibility of the support technique and provides theoretical value for active adjustment in the laboratory. At present support and adjusting experiment of ultra thin mirror is being carried on.

Grating interferometry method for torsion measurement (EI CONFERENCE) 会议论文 OAI收割
ICO20: Optical Information Processing, August 21, 2005 - August 26, 2005, Changchun, China
作者: Liu W.

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Method of grating interferometry was presented for torsion angle measurement moire fringe generated by two gratings is used in a new field it breaks through moire fringe's routine application. Measurement principle is described torsion angle can be gotten by the tilt angle or the width of moire fringe. Different from moire fringe's characteristic information extracting methods in traditional measurement fields fringe-tilt method and fringe-width method were put forward to extract moire fringe's characteristic information. Fringe-tilt method is on the basis of moire fringe's tilt to acquire torsion angle uniform formula was built aiming at all positions of two gratings in the coordinates fringe-width method is on the basis of moire fringe's width to acquire torsion angle three key problems are given about fringe-width method. Thick middle and thin moire fringe were collected in experiments and processed by two methods fringe-width method's result shows that magnitude of boat torsion error is satisfied with that of theoretical precision analysis and the change rule of torsion error is also same to that of theoretical analysis the thicker fringe is the higher precision is when fringe width arrives to be 1695m the precision is 1.7" the thinner fringe is the lower precision is when fringe width arrives to be 734.7m the precision is 6.7". In addition to these the results of repeatability experiments sensibility experiments are given. In a word the measurement principle is right and the precision of fringe processing is also reliable.