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中国科学院机构知识库网格

Chinese Academy of Sciences Institutional Repositories Grid

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	Real-time adjusting of yaw angle of space camera based on General Image-Quality Equation (EI CONFERENCE) 会议论文 OAI收割 2009 2nd International Conference on Intelligent Computing Technology and Automation, ICICTA 2009, October 10, 2009 - October 11, 2009, Changsha, Hunan, China 作者: Wang J.; He X.; Xu S. 收藏 \| 浏览/下载：18/0 \| 提交时间：2013/03/25 A Strategy of Real-Time Adjusting of Yaw Angle (SRTAYA) of space camera was proposed base on General Image-Quality Equation (GIQE). During space camera imaging yaw angle which is caused by rotation of the earth and the gesture changing of satellite impacts integral aspect of TDI (Time Delay and Integration) CCD (Charge Couple Device) so that the image quality degrades. For extending imaging time of space camera and enhancing image quality yaw angle must be adjusted. The descending value of GIQE reflects the degrading quantity of image quality. The SRTAYA calculated an acceptable augmenting value of yaw angle according with a specific value of GIQE which the degrading of image quality can't be neglected no longer. The example which actualized a practical orbit of satellite illuminated that the SRTAYA could limit the value of yaw angle less than 318.45". 2009 IEEE.
	Modeling of satellite borne TDI CCD pitching imaging image motion velocity vector (EI CONFERENCE) 会议论文 OAI收割 2009 IEEE International Conference on Automation and Logistics, ICAL 2009, August 5, 2009 - August 7, 2009, Shenyang, China 作者: Zhang L.; Li S.; Zhang L. 收藏 \| 浏览/下载：12/0 \| 提交时间：2013/03/25 In order to obtain three-dimensional observation effect with single satellite borne time delay and integrate charge coupled device (TDI-CCD) pitching imaging is required. More accurate real-time image motion velocity vector computational model of space camera is also necessary to make the imaging perfect. Imaging motion velocity vector computation model must be set up on image plane at pitching imaging. According to the geometric relationship between the pitching imaging space camera and the Earth's rotation motion satellite borne TDI CCD pitching imaging motion velocity vector model is derived by mapping the ground speed to the image plane and using coordinate transformation method. The numerical simulation results show that the image velocity model can reduce deviation angle error about 33' and about 30% image motion speed error compared to traditional ground velocity model. 2009 IEEE.
	Space camera imaging gain in-orbit adjusting strategy (EI CONFERENCE) 会议论文 OAI收割 2009 2nd International Conference on Intelligent Computing Technology and Automation, ICICTA 2009, October 10, 2009 - October 11, 2009, Changsha, Hunan, China 作者: Wang J.; He X. 收藏 \| 浏览/下载：10/0 \| 提交时间：2013/03/25 A Multi-Step Gain Adjusting Strategy (MSGAS) of space camera was proposed which was used to get higher SNR (Signal-Noise Rate) image. When the space camera working in poor light condition the CCD signal was so weak that it's difficult to get a clear image to reduce the quantization noise and improve the SNR we must amplify the CCD signal first and then quantize. The MSGAS was achieved by adjusting the gain of the CCD (Charge Couple Device) signal processor step by step the upper limit and lower limit were set if the MDN (Mean Digital Number) of a fixed length image data was not between the lower and upper limit the gain was adjusted step by step. In the experiment the upper limit lower limit and the step were set and the result of the experiment showed that MSGAS was robust and SNR was improved from 28 to 39. 2009 IEEE.