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Signal synthesis of time-domain electromagnetic response excited by a pseudo random binary sequence source 期刊论文  OAI收割
CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION, 2016, 卷号: 59, 期号: 12, 页码: 4414-4423
作者:  
Wang, Ruo;  Wang, Miao-Yue;  Di, Qing-Yung;  Xue, Guo-Qiang;  Yin, Chang-Chun
  |  收藏  |  浏览/下载:25/0  |  提交时间:2017/11/20
Research of active supporting technology based on 400mm thin mirror (EI CONFERENCE) 会议论文  OAI收割
5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Large Mirrors and Telescopes, April 26, 2010 - April 29, 2010, Dalian, China
作者:  
Liu X.-Y.;  Wang J.-L.;  Wang J.-L.;  Liu X.-Y.
收藏  |  浏览/下载:31/0  |  提交时间:2013/03/25
Using a spherical mirror of 400mm diameter and 12mm thickness  active supporting technology of thin mirror is researched. The axial support of the mirror is composed of 12 active supports and 3 fixed supports. The force actuator  which is composed of displacement actuator and force sensor  is installed in the active support. The mirror surface is tested by Zygo interferometer. For calibration  each actuator exerts unit force alone  and the surface variation is tested and taken as the response function of the actuator. The response functions of all actuators compose the stiffness matrix. Then the stiffness matrix is used by damped least square method to determine the correction force of each active support. In order to analyze the correction capability of the active supports  14 Zernike modes of the mirror surface are generated and tested respectively  and 7 modes are selected for correction. Initially  the RMS error of mirror surface is 1.16 I( =0.6328nm)when all actuators exert the same force. After 5 iterations  the RMS error of mirror surface is reduced to 0.13  close to the original surface quality. 2010 Copyright SPIE - The International Society for Optical Engineering.  
Attitude determination of small, dim and high-speed targets based on multi-CMOS intersecting system (EI CONFERENCE) 会议论文  OAI收割
2nd International Conference on Information Science and Engineering, ICISE2010, December 4, 2010 - December 6, 2010, Hangzhou, China
作者:  
Li M.;  Zhao L.;  Wang J.
收藏  |  浏览/下载:34/0  |  提交时间:2013/03/25
In order to measure attitude of small  dim and high-speed targets in shooting range  intersecting system based on multiple high-speed CMOS cameras was introduced in this paper. CMOS cameras were laid near from objects for small size  using multiple CMOS cameras to compose intersecting system for big number of targets tested  and selecting CMOS camera between CMOS and CCD for low cost and considering damage to measurement equipment of objects tested. Pitch angle and yaw angle were measured by extracting axle wire through image processing  image sequences were obtained from cameras laying on two sides. Velocity of objects was calculated by least square curve-fitting  acquiring coordinate of centroid on image received by CMOS camera laying below effective viewing field. One CMOS camera was laid on right ahead for measuring roll angle. Station mode introduced in this paper has virtue of low cost and free extending. 2010 IEEE.  
Storage and compression design of high speed CCD (EI CONFERENCE) 会议论文  OAI收割
4th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optical Test and Measurement Technology and Equipment, November 19, 2008 - November 21, 2008, Chengdu, China
Cai X.; Zhai L. P.
收藏  |  浏览/下载:62/0  |  提交时间:2013/03/25
In current field of CCD measurement  large area and high resolution CCD is used to obtain big measurement image  so that  speed and capacity of CCD requires high performance of later storage and process system. The paper discusses how to use SCSI hard disk to construct storage system and use DSPs and FPGA to realize image compression. As for storage subsystem  Because CCD is divided into multiplex output  SCSI array is used in RAID0 way. The storage system is composed of high speed buffer  DMA controller  control MCU  SCSI protocol controller and SCSI hard disk. As for compression subsystem  according to requirement of communication and monitor system  the output is fixed resolution image and analog PAL signal. The compression means is JPEG2000 standard  in which  9/7 wavelets in lifting format is used. 2 DSPs and FPGA are used to compose parallel compression system. The system is composed of FPGA pre-processing module  DSP compression module  video decoder module  data buffer module and communication module. Firstly  discrete wavelet transform and quantization is realized in FPGA. Secondly  entropy coding and stream adaption is realized in DSPs. Last  analog PAL signal is output by Video decoder. Data buffer is realized in synchronous dual-port RAM and state of subsystem is transfer to controller. Through subjective and objective evaluation  the storage and compression system satisfies the requirement of system. 2009 SPIE.