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浏览/检索结果: 共12条，第1-10条 帮助 限定条件 内容类型：会议论文     已选(0)清除 条数/页：5101520253035404550556065707580859095100   排序方式：请选择作者升序作者降序题名升序题名降序发表日期升序发表日期降序提交时间升序提交时间降序 Research on energy characteristics of aerospace relay mirror system (EI CONFERENCE) 会议论文 2011 International Conference on Electronic and Mechanical Engineering and Information Technology, EMEIT 2011, August 12, 2011 - August 14, 2011, Harbin, China Liu C.; Zhong X.; Piao Y.; Jin G. 收藏  |  浏览/下载：21/0  |  提交时间：2013/03/25 Aerospace Relay Mirror System (ARMS) as a new concept weapon used in reflection of High Energy Laser (HEL) in space is studied. It extends the attacking range of Ground Based Laser (GBL) weapons enormously. Relevant researches have been carried out for many years. The structures and operating theory of the entire system consists of ground-based high energy laser weapon and space-based relay mirror. The main work of this study is focused on the analysis of relay mirror energy characteristics to deduce the relationship among the attacking range of weapon and diameter of ARMS and target irradiance. Calculation examples are also given. The results proved the strong points and feasibility of ARMS theoretically further. It is summarized that more importance should be attached to ARMS development. The results given in this paper can be reference of an actual ARMS system to some extends. 2011 IEEE.   Design of motion compensation mechanism of satellite remote sensing camera (EI CONFERENCE) 会议论文 International Symposium on Photoelectronic Detection and Imaging 2011: Space Exploration Technologies and Applications, May 24, 2011 - May 26, 2011, Beijing, China Gu S.; Yan Y.; Xu K.; Jin G. 收藏  |  浏览/下载：37/0  |  提交时间：2013/03/25 With the development of aerospace remote sensing technology  the ground resolution of remote sensing camera enhances continuously. Since there is relative motion between camera and ground target when taking pictures  the target image recorded in recording media is moved and blurred. In order to enhance the imaging quality and resolution of the camera  the image motion had to be compensated. In order to abate the effect of image motion to image quality of space camera and improve the resolution of the camera  the compensation method of image motion to space camera is researched. First  the reason of producing drift angle and adjustment principle are analyzed in this paper. This paper introduce the composition and transmission principle of image motion compensation mechanism. Second  the system adopts 80C31 as controller of drift angle  and adopts stepping motor for actuators  and adopts absolute photoelectric encoder as the drift Angle measuring element. Then the control mathematical model of the image motion compensation mechanism are deduced  and it achieve the closed-loop control of the drift angle position. At the last  this paper analyses the transmission precision of the mechanism. Through the experiment  we measured the actual precision of the image motion compensation mechanism  and compared with the theoretical analysis. There are two major contributions in this paper. First  the traditional image motion compensation mechanism is big volume and quality heavy. This has not fit for the development trend of space camera miniaturization and lightweight. But if reduce the volume and quality of mechanism  it will bring adverse effects for the precision and stiffness of mechanism. For this problem  This paper designed a image motion compensation that have some advantages such as small size  light weight at the same time  high precision  stiffness and so on. This image motion compensation can be applicable to the small optics cameras with high resolution. Second  the traditional mechanism control need to corrected  fitting and iterative for the control formula of mechanism. Only in this way  we can get the optimal control mathematical model. This paper has high precision of the control formula derived. It can achieve the high precision control without fitting  It also simplify the difficulty of control mathematical model establishment. This paper designed the range of adjusting of image motion compensation mechanism between -5 +5. Based on choosing-5  -4  -3  -2  -1  0  +1  +2  +3  +4  +4 as the expectation value of the imaginary drift angle  we get ten groups of the fact data in adjusting drift angle measured. The test results show that the precision of the drift angle control system can be achieved in 1. It can meet the system requirements that the precision of the control system is less than 3'  and it can achieve the high-precision image motion compensation. 2011 SPIE.   Adaptive Wiener filtering with Gaussian fitted point spread function in image restoration (EI CONFERENCE) 会议论文 2011 IEEE 2nd International Conference on Software Engineering and Service Science, ICSESS 2011, July 15, 2011 - July 17, 2011, Beijing, China Yang L.; Zhang X.; Ren J. 收藏  |  浏览/下载：29/0  |  提交时间：2013/03/25 In the imaging process of the space remote sensing camera  there was degradation phenomenon in the acquired images. In order to reduce the image blur caused by the degradation  the remote sensing images were restored to give prominence to the characteristic objects in the images. First  the frequency-domain notch filter was adopted to remove strip noises in the images. Then using the ground characters with the knife-edge shape in the images  the point spread function of the imaging system was estimated. In order to improve the accuracy  the estimated point spread function was corrected with Gaussian fitting method. Finally  the images were restored using the adaptive Wiener filtering with the fitted point spread function. Experimental results of the real remote sensing images showed that almost all strip noises in the images were eliminated. After the denoised images were restored  its variance and its gray mean gradient increased  also its laplacian gradient increased. Restoration with Gaussian fitted point spread function is beneficial to interpreting and analyzing the remote sensing images. After restoration  the blur phenomenon of the images is reduced. The characters are highlighted  and the visual effect of the images is clearer. 2011 IEEE.   High precision test method for dynamic imaging of space camera (EI CONFERENCE) 会议论文 2010 IEEE International Conference on Advanced Computer Control, ICACC 2010, March 27, 2010 - March 29, 2010, 445 Hoes Lane - P.O.Box 1331, Piscataway, NJ 08855-1331, United States Zheng G.-F.; Ma S.-F.; Sun J.-G.; Jin L.-X.; Zhang K. 收藏  |  浏览/下载：19/0  |  提交时间：2013/03/25 A test method for dynamic imaging of space TDICCD (Time Delay and Integration Charge Coupled Devices) camera was presented in this paper. The test method adopted the PLL (Phase Locked Loop) technology and CMAC (Cerebella Model Articulation Controller) friction compensation as control strategy. Furthermore  According to this method  a test system for dynamic imaging of space TDICCD camera was designed and implemented. The system simulated the movement of the ground objects relative to the space aerocraft  to validate the capability of image speed match and the dynamic imaging quality of TDICCD camera. The design adopted a precision turntable and a drift turntable to simulate the movement around the earth and the drift motion in different latitude due to the rotation of earth  of the aerocraft. The turntables were drived by permanent magnet torque motor which was powered by PWM (Pulse Width Modulation). The system adopted DSP (Digital Signal Processor) as the control core and reached a very high performance. The experimental results showed that the steady speed error was better than 0.01 % and the instantaneous speed error reached 0.0267%. The precision of the test system designed met the requirement for dynamic imaging of TDICCD camera. 2010 IEEE.   Inspection focus technology of space tridimensional mapping camera based on astigmatic method (EI CONFERENCE) 会议论文 5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optoelectronic Materials and Devices for Detector, Imager, Display, and Energy Conversion Technology, April 26, 2010 - April 29, 2010, Dalian, China Wang Z.; Zhang L. 收藏  |  浏览/下载：16/0  |  提交时间：2013/03/25 The CCD plane of the space tridimensional mapping camera will be deviated from the focal plane(including the CCD plane deviated due to camera focal length changed)  under the condition of space environment and vibration  impact when satellite is launching  image resolution ratio will be descended because defocusing. For tridimensional mapping camera  principal point position and focal length variation of the camera affect positioning accuracy of ground target  conventional solution is under the condition of vacuum and focusing range  calibrate the position of CCD plane with code of photoelectric encoder  when the camera defocusing in orbit  the magnitude and direction of defocusing amount are obtained by photoelectric encoder  then the focusing mechanism driven by step motor to compensate defocusing amount of the CCD plane. For tridimensional mapping camera  under the condition of space environment and vibration  impact when satellite is launching  if the camera focal length changes  above focusing method has been meaningless. Thus  the measuring and focusing method was put forward based on astigmation  a quadrant detector was adopted to measure the astigmation caused by the deviation of the CCD plane  refer to calibrated relation between the CCD plane poison and the asrigmation  the deviation vector of the CCD plane can be obtained. This method includes all factors caused deviation of the CCD plane  experimental results show that the focusing resolution of mapping camera focusing mechanism based on astigmatic method can reach 0.25 m. 2010 Copyright SPIE - The International Society for Optical Engineering.   Manufacture of 1.2m reaction bonded silicon carbide mirror blank CFID (EI CONFERENCE) 会议论文 5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Large Mirrors and Telescopes, April 26, 2010 - April 29, 2010, Dalian, China Zhang G.; Zhao R.; Zhao W.; Bao J. 收藏  |  浏览/下载：16/0  |  提交时间：2013/03/25 Silicon carbide (SiC) is a new type candidate material for large-scale lightweight space mirror. Its low thermal distortion  high stiffness  fine optical quality and dimensional stability  make SiC an ideal material for large space born telescope. Since ten years Changchun institute optics  fine mechanics and physics (CIOMP) has developed reaction bonded SiC (RB-SiC) technology for space application  and can fabricate RB-SiC mirror with scale less than 1.0 meter for telescope. The green body is prepared with gel-casting method which is an attractive new ceramic forming process for making high-quality  complex-shaped ceramic parts. And then unmolding  drying  binder burning out  reacting bonded  the RB-SiC can be obtained. But with the development of space-born or ground telescope  the scale of primary mirror has exceeded 1.0 meter. So CIOMP has developed an assembly technique which called novel reaction-formed joint technology for larger RB-SiC mirror blank. The steps include joining of green bodies with mixture comprised of SiC particles and phenolic resin etc  firing  machining and sintering. Joining the 1.2 meter RB-SiC mirror blank by the novel reaction-formed joint technology. And testing the welding layer's performance  the results show that the thickness of 54-77m  the microstructure and thermal property can be comparable to the substrate and the mechanical property are excellent in bending strength of 307MPa. 2010 Copyright SPIE - The International Society for Optical Engineering.   Validation of the dust layer structure over the Taklimakan Desert, China by the CALIOP space-borne lidar using ground-based lidar - Part II 会议论文 Proceedings of SPIE - The International Society for Optical Engineering, Remote Sensing and Modeling of the Atmosphere, Oceans, and Interactions III, Incheon, Korea, Republic of, 2010 Jin; Yoshitaka1; Kai; Kenji1; Shibata; Takashi1; Zhang; Kecun2; Zhou; Hongfei3 收藏  |  浏览/下载：36/0  |  提交时间：2011/08/23 Aerosol optical depths - Aerosols and clouds - Backscatter profiles - Backscattering coefficients - Backscattering ratio - CALIPSO - Cirrus clouds - Color ratios - Correlation coefficient - Dust layer - Ground based - Level 2 - lidar - Lidar observation - Lidar ratio - Performance functions - Space-borne lidar - Taklimakan desert - Tropospheric aerosolsC   Level 0 and level 1 data processing for a type of hyper-spectral imager (EI CONFERENCE) 会议论文 2009 International Conference on Optical Instruments and Technology, OIT 2009, October 19, 2009 - October 21, 2009, Shanghai, China Li X.; Yan C. 收藏  |  浏览/下载：62/0  |  提交时间：2013/03/25 Hyper-spectral imaging (HSI) is a kind of optical remote sensor that can simultaneously obtain spatial and spectral information of ground targets. We are now designing a data processing system for a type of space-borne push-broom HSI  then it performs radiometric and spectral calibration based on the ground calibration results and onboard calibration collection. The detailed algorithms for bad pixel replacement  which has 128 spectral channels covering the spectral range from 400nm to 2500nm. With its large amount of spectral channels  radiometric and spectral calibration were presented. After processing  the HSI collects large volume of spectral imaging data need to be efficiently and accurately processed and calibrated. In this paper  the digital numbers downlinked from the spacecraft can be converted into at-sensor absolute spectral radiance of ground targets  the detailed Level 0 and Level 1 data processing steps for the HSI were presented. The Level 0 processing refers to a set of tasks performed on the data downlinked from the spacecraft  thus providing accurate quantified spectral imaging data for various applications. 2009 SPIE.  including decoding to extract science data  separating the science data into files corresponding to different tasks (e.g. ground imaging  dark imaging  and onboard calibration)  checking data integrity and instrument settings  data format conversion  and Level 0 files creation. The Level 1 processing performs several steps on Level 0 data. Firstly  it corrects the image artifacts (mostly the SWIR smear effect)  subtracts the dark background  and performs the bad pixel replacement according to the prelaunch measurement   Design of optical lens for space tridimensional mapping camera (EI CONFERENCE) 会议论文 4th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Advanced Optical Manufacturing Technologies, November 19, 2008 - November 21, 2008, Chengdu, China Zhang L.-P.; Wang Z. 收藏  |  浏览/下载：15/0  |  提交时间：2013/03/25 Three-linear array tridimensional mapping camera consists of three independent linear CCD cameras. Unique position must be kept among the three linear CCD cameras. Optical lens is one of pivotal parts  MTF  the ground resolution power is 5m  resolving power  the distortion is 3/10000. They meet the need of user. 2009 SPIE.  distortion are its important techno-items. The optical lens of space tridimensional mapping camera is the key to accomplish the tridimensional mapping mission. In order to meet the need of user  a design on optical lens of transmission semi-telecentric beam path in image space is expounded  and assembly method based on DFT(Design For Test) of single lens suit and whole optical lens are expounded. The test results indicates that the MTF of optical lens referred in the paper is 0.45(@77lp/mm)   Optical system of large relative aperture and wide field using aspheric corrector for detecting (EI CONFERENCE) 会议论文 4th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Advanced Optical Manufacturing Technologies, November 19, 2008 - November 21, 2008, Chengdu, China Ming M.; Wang J.; Zhang J. 收藏  |  浏览/下载：15/0  |  提交时间：2013/03/25 The magnitude requirement of space target detecting determines that the image of detecting telescope should have several performances: small spots  the wider field of view  small 80% encircled energy diameter and good MTF(Modulation transfer function). So the aperture and field of view of optical system have some demands accordingly. The larger aperture  the more extensive range which the telescope searches. Now most of ground telescopes whose apertures are from 500mm to 1000mm is on-axis optical system  the more energy that telescope collects and higher magnitude the telescope detects  so wide field of view becomes the most importance problem. To obtain large relative aperture and wide field of view  the paper introduces a catadioptric telescope with small aperture aspheric refractive corrector  whose conic surface will be used to remove the aberrations due to large relative aperture and wide field of view. As to the optical system  there is only one aspheric refractive corrector  and it is relatively easy for manufacturing because of its concave figure and normal material. The paper gives the example  and optimizes this optical system with ZEMAX program. And then the paper provides a specific analysis program for testing the aspheric refractive corrector. The aperture of this optical system is 750mm  and its relative aperture is 0.82  and the field of view is 3.6 diameter(diagonal). Its structure is simple and the image quality is also very good. 2009 SPIE.