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Chinese Academy of Sciences Institutional Repositories Grid

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	A new low-bandwidth and wireless transmission scheme for CCd image (EI CONFERENCE) 会议论文 OAI收割 2012 International Symposium on Photonics and Optoelectronics, SOPO 2012, May 21, 2012 - May 23, 2012, Shanghai, China 作者: Zhang Y. 收藏 \| 浏览/下载：40/0 \| 提交时间：2013/03/25 The CCD (Charge-coupled Device) image sensor with its high resolution is capable of providing high definition image. However transmission requires high bandwidth which makes it very difficult to process and transmit in a long distance. The purpose of this paper is to propose a new method to process and transmit CCD image which can guarantee a low-bandwidth and long-distance data transmission. The innovation is that the transmission content of CCD image data can be flexibly selected and compressed firstly which will reduce the transmission data. Then it is processed on the base of communication protocol so that it can be fit for wireless transmission. At last it is transformed into wireless signal and transmitted using 3G technology. As a result the paper presents a wireless transmission scheme with the rate of 1.5Mbps for CCD image. 2012 IEEE.
	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. 收藏 \| 浏览/下载：35/0 \| 提交时间：2013/03/25 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.
	A high-accuracy parameter estimation algorithm for jointless Frequency-shift track circuit (EI CONFERENCE) 会议论文 OAI收割 ISECS International Colloquium on Computing, Communication, Control, and Management, CCCM 2008, August 3, 2008 - August 4, 2008, Guangzhou, China 作者: Zheng X. 收藏 \| 浏览/下载：31/0 \| 提交时间：2013/03/25 FSK (Frequency Shift keying) signal which has advantages of narrow-bandwidth strong anti-interference ability long transmission distance and so on is used in jointless Frequency-shift track circuit to send different kinds of control signals. However as FSK is non-linearly modulated parameter estimation with high accuracy is hard to realize. Based on the spectrum analysis complement with time-frequency distribution a highaccuracy FSK signal parameter estimation algorithm is put forward in this paper. According to the signal characteristics under-sampling and ZFFT are used to improve the accuracy of spectrum analysis and the base frequency resolution meets system requirement of 0.02Hz. Wigner-Ville distribution has an excellent time-frequency concentration while serious cross-term interference at the same time. Through the design of kernel function the cross-terms are almost suppressed and the upper/down side frequency resolution meets the system requirement of 0.2Hz. The effectivities of all the methods mentioned above have been proved by MATLAB simulation which pave a solid way for the development of high-accuracy FSK signal parameter estimation devices. 2008 IEEE.