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Statistical Characteristics of Evaporating-Freezing Process of Water Droplet during Quick Depressurization 会议论文  OAI收割
Asian Microgravity Pre-Symposium 9th China-Japan-Korea Workshop on Microgravity Sciences, 中国广西桂林/Guilin, China, 2012-10-29
作者:  
Du WF(杜王芳);  Zhao JF(赵建福);  Kang Q(康琦)
收藏  |  浏览/下载:50/0  |  提交时间:2014/04/02
The research of the accurate measure of static transfer function for the TDI CCD camera (EI CONFERENCE) 会议论文  OAI收割
3rd International Photonics and OptoElectronics Meetings, POEM 2010, November 2, 2010 - November 5, 2010, Wuhan, China
Guo-Ning L.; Long-Xu J.; Jian-Yue R.; Wen-Hua W.; Shuang-Li H.
收藏  |  浏览/下载:28/0  |  提交时间:2013/03/25
In the test course of static transfer function of TDI CCD camera  because of the influence that gets environmental and artificial etc. factor  the value of static transfer function measured at any time is between unceasing fluctuation  so  make accuracy reduce. To solve this problem  a kind of accurate measurement technique of static transfer function is put forward. First  before carrying out the measure of static quiet of transfer function  the best test point of transfer function of the TDI CCD camera must be determined  it is parallel to guarantee the rectangle target surface of parallel optical pipe and camera focal plane maintenance parallel  and again guarantee target strip in rectangle target and TDI CCD in camera focal plane maintenance vertical. TDI CCD catches rectangle target image  per 1000 lines of target mark image as a measures sample of static transfer function  exclude because of atmosphere tremble twisted  vague rectangle target mark image  retain 500 distinct and steady target mark image as measure sample set. Then  calculate the static transfer function of each measure sample respectively  take the average of all static quiet transfer function in measure sample set as the static transfer function of camera. Finally  the measure of the static transfer function for TDI CCD camera makes error analysis. Experimental results indicate that the value of the static transfer function of TDI CCD camera measured with this kind of method is 0.2923  with before measurement technique comparison  the value of static transfer function has raised 0.02  makes the accuracy of the measure of static transfer function have gotten raising.  
Method of auto multi-exposure for high dynamic range imaging (EI CONFERENCE) 会议论文  OAI收割
2010 International Conference on Computer, Mechatronics, Control and Electronic Engineering, CMCE 2010, August 24, 2010 - August 26, 2010, Changchun, China
Piao Y.; Xu W.
收藏  |  浏览/下载:26/0  |  提交时间:2013/03/25
This paper proposes a method for calculating the multi-exposure times fast and accurately when the scene has a high dynamic range  minimizing the pictures needed to take and improving the dynamic range of the CCD system. The proposed method first measures the camera's response function referring [10]. After that the median value of the output picture is adjusted to be in the middle range of the system output by changing the exposure time. It can be inferred from the histogram of the current picture whether it's a high dynamic range scene by calculating the number of pixels under exposed and over exposed. Once again the under and over exposed pixels are adjusted to be in the middle according to the camera's response function. Finally different exposed pictures (2 or 3) are fused together by Gaussian function and the dynamic range is compressed by y correction. Experimental results on UNIQ-UM400 analog camera and a digital acquisition system show that the algorithm works well and solve the problem of low dynamic range of CCD camera. 2010 IEEE.  
Mid-frequency surface error test with a Foucault apparatus (EI CONFERENCE) 会议论文  OAI收割
3rd International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optical Test and Measurement Technology and Equipment, July 8, 2007 - July 12, 2007, Chengdu, China
作者:  
Li J.;  Li J.;  Xuan B.;  Li J.
收藏  |  浏览/下载:20/0  |  提交时间:2013/03/25
Testing of mid-frequency surface error is of the first importance for fast optics  especially for large aperture aspherics. Foucault test plays a dominant role for surface error inspection before the digital interferometer age  but it seems to have faded out these days because no quantitative results turn out. However  an interferometer with high resolution CCDs is either unavailable or unaccessible in the process of manufacture. As its advantages are realized and recognized for the second time  Foucault test is going back to the stage again. A new theory of calculating the contrast of the shadow pattern of Foucault test is put forward in this paper and some modifications are discussed upon the analyses of the limitation of traditional Foucault apparatus. A paraboloidal mirror was fabricated and tested by the modified Foucault apparatus whose effect has been proved to be great. The methods of controlling mid-frequency error are described in the other paper at this conference- "Multi-mode combine manufacturing technology for large aperture aspheric mirrors"1.  
A deep-space trail forecast method based on the enlargement of field of view (EI CONFERENCE) 会议论文  OAI收割
16th International Conference on Artificial Reality and Telexistence - Workshops, ICAT 2006, November 29, 2006 - December 1, 2006, Hangzhou, China
Han Q.; Yao Z.; Zhu M.
收藏  |  浏览/下载:27/0  |  提交时间:2013/03/25
During the procedure of target tracing  lots of stars will cross the field of view. These stars will disturb the procedure and  the precision of system will be degraded. At the same time  because the optical surveillance system is limited by environment  the targets are often covered by clouds. The above situations will seriously degrade the system's robustness  and once the target is disappeared  the traditional system can't track the target again. Traditional forecast methods merely use coder information  so the precision is low. In order to upgrade the precision  we combine the coder information and the missdistance to forecast the next frame target position. The method is based on field range enlargement. Proved by practical experiments  this method can effectively improve the robustness of the target tracking system. 2006 IEEE.