2011
2011
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Record 61 of
Title:Simultaneous sensing of displacement and temperature with a single FBG
Author(s):Wei, Ting(1,2); Qiao, Xue-Guang(1,2); Jia, Zhen-An(1)Source: Optoelectronics Letters Volume: 7 Issue: 1 DOI: 10.1007/s11801-011-0014-2 Published: January 2011Abstract:A novel fiber Bragg grating (FBG) sensor with simultaneous sensing of displacement and temperature is presented. The FBG is affixed on the cantilever inclinedly. The midpoint of FBG exactly coincides with the zero strain layer of a rectangular beam. The vertical displacement can be measured by the broadened bandwidth of FBG as the bandwidth is insensitive to temperature, while the temperature can be measured by the center wavelength shift as the wavelength shift is insensitive to vertical displacement. With 0.1 nm spectral resolution of the analyzer, sensitivities of bandwidth-displacement and center wavelength-temperature are 0.48 nm/mm and 0.05 nm/°C, resolutions are 0.2 mm and 2.0 °C, and sensing ranges of displacement and temperature are up to 8.5 mm and 45°C respectively. Experimental results match theoretical analyses very well. ? Tianjin University of Technology and Springer-Verlag Berlin Heidelberg 2011.Accession Number: 20112114009695 -
Record 62 of
Title:Implementation of a LMS filter on FPGA employing extremeDSP and smart IP-core design
Author(s):Wang, Yaqin(1); Liu, Xuebin(1); Hu, Bingliang(1)Source: Proceedings - IEEE 2011 10th International Conference on Electronic Measurement and Instruments, ICEMI 2011 Volume: 3 Issue: DOI: 10.1109/ICEMI.2011.6037920 Published: 2011Abstract:Field Programmable Gate Arrays have become popular platform for digital signal processing, however, the conventional method, which is essentially writing a source code in a hardware description language to design a product on a FPGA, is time consuming and complicated. This restricts the implementation of complex signal processing algorithm on FPGA. In this paper, two fast design methods of algorithm implementation on FPGA were proposed: ExtremeDSP solution and Smart IP-Core technology. The AccelDSP Synthesis tool, as the main component of ExtremeDSP solution allows transferring a MATLAB floating point design into a hardware module that can be implemented on a Xilinx FPGA. Employing predefined cores can cut the design time and significantly reduce risk while having access to the best performing and lowest cost component available. Implementation of a LMS-adaptive filter employing these two methods has been achieved and the simulation results indicate that both of the two fast designs have high performance. ? 2011 IEEE.Accession Number: 20114414464820 -
Record 63 of
Title:Design proposal of a Fourier telescopy transmitter for moving objects in low earth orbit
Author(s):Luo, Xiu-Juan(1); Ma, Cai-Wen(1); Zhang, Yu(1); Si, Qing-Dan(1)Source: Shenzhen Daxue Xuebao (Ligong Ban)/Journal of Shenzhen University Science and Engineering Volume: 28 Issue: 4 DOI: Published: July 2011Abstract:For the purpose of using high-resolution to detect and identify low earth orbit (LEO) moving space objects, a proposal of the Fourier telescopy transmitter array disposition was presented, and a single transmitter was designed. The proposed transmitter system integrated the atmospheric aberration measurement system, the feedback control system, and the target tracking system. It used atmospheric turbulence wave-front correction and correlative tracking techniques to achieve accurate tracking of fast moving objects, simultaneously emitted multiple interference laser beams sweeping across the target to improve imaging speed, and carried out computer simulation on interference between laser beam pairs and laser propagation along slant paths through turbulence atmosphere. Theoretical analysis and simulation results show that the design from the proposal is reasonably feasible and meets the goal of the rapid LEO objects imaging on Fourier telescopy transmitter design.Accession Number: 20113314234894 -
Record 64 of
Title:Design and application of TEC controller Using in CCD camera
Author(s):Gan, Yu-Quan(1); Ge, Wei(1); Qiao, Wei-Dong(1); Lu, Di(1); Lv, Juan(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 8196 Issue: DOI: 10.1117/12.900697 Published: 2011Abstract:Thermoelectric cooler (TEC) is a kind of solid hot pump performed with Peltier effect. And it is small, light and noiseless. The cooling quantity is proportional to the TEC working current when the temperature difference between the hot side and the cold side keeps stable. The heating quantity and cooling quantity can be controlled by changing the value and direction of current of two sides of TEC. So, thermoelectric cooling technology is the best way to cool CCD device. The E2V's scientific image sensor CCD47-20 integrates TEC and CCD together. This package makes easier of electrical design. Software and hardware system of TEC controller are designed with CCD47-20 which is packaged with integral solid-state Peltier cooler. For hardware system, 80C51 MCU is used as CPU, 8-bit ADC and 8-bit DAC compose of closed-loop controlled system. Controlled quantity can be computed by sampling the temperature from thermistor in CCD. TEC is drove by MOSFET which consists of constant current driving circuit. For software system, advanced controlled precision and convergence speed of TEC system can be gotten by using PID controlled algorithm and tuning proportional, integral and differential coefficient. The result shows: if the heat emission of the hot side of TEC is good enough to keep the temperature stable, and when the sampling frequency is 2 seconds, temperature controlled velocity is 5°C/min. And temperature difference can reach -40°C, controlled precision can achieve 0.3°C. When the hot side temperature is stable at 25°C, CCD temperature can reach -23°C, and thermal noise of CCD is less than 1e-/pix/s. The controlled system restricts the dark-current noise of CCD and increases SNR of the camera system. ? 2011 SPIE.Accession Number: 20113614296278 -
Record 65 of
Title:Infrared automatic capture technology on shipborne photoelectric tracking system
Author(s):Qiao, Yongming(1); Hao, Wei(1); Tian, Guangyuan(1); Han, Junfeng(1)Source: Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering Volume: 40 Issue: 4 DOI: Published: April 2011Abstract:Aiming at the characteristics of shipborne photoelectric tracking system that works under mobile pedestal and complicated sea background, a method of using a mathematics platform for line of sight (LOS) stabilization was proposed. Using strapdown inertial navigation system (SINS) and offset staff adjustment on line, the zero steady-state angle error of LOS dynamic collimation was realized when there was no infrared tracking feedback. Moreover, the interference of complicated sea background has been restrained by designating an infrared image area based on prior knowledge and the capability and stability of automatic capture based mobile pedestal have been enhanced. Now, this system is placed at a small warship of which dead weight is only 700 tons, then the probability of independent capture is more than 95% under four-grate sea condition.Accession Number: 20112714112344 -
Record 66 of
Title:HDR image synthesis based on multi-exposure color images
Author(s):Wang, Hua(1); Cao, Jianzhong(1); Tang, Linao(1); Tang, Yao(1)Source: Lecture Notes in Electrical Engineering Volume: 132 LNEE Issue: VOL. 1 DOI: 10.1007/978-3-642-25899-2_16 Published: 2011Abstract:In digital camera, it's difficult to exceed the dynamic range of 60~80dB because of the saturation current and background noise of CCD/CMOS image sensor in a single exposure image. In order to obtain more information and detail of a scene, we should extend its dynamic range, which was called HDR technology. Recent years, HDR imaging techniques have become the focus of much research because of their high theoretical and practical importance. By applying HDR techniques, the performance of different image processing and computer vision algorithms, information enhancement, and object and pattern recognition can also be improved. In this paper, a new tone reproduction algorithm is introduced, based on which may help to develop the hard-to-view or nonviewable features and details of color images. This method applies on multi-exposure images synthesis technique, where the red, green, and blue (RGB) color components of the pixels are separately handled. In the output, the corresponding (modified) color components are blended. As a result, a high quality HDR image is obtained, which contains almost the whole details and color information. ? 2011 Springer-Verlag.Accession Number: 20120814781272 -
Record 67 of
Title:Laser protection of optical payload
Author(s):Li, Fu(1); Yang, Jianfeng(1); Ruan, Ping(1); Xue, Bin(1)Source: Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering Volume: 40 Issue: 9 DOI: Published: September 2011Abstract:The optical payload is aircraft's "eye", which is attacked by laser weapons very easily. Now, the ground-based laser weapons have possessed actual combat ability and their performance was influenced by their parameters and atmosphere. The disturbed and destroyed principle of optical payload by laser weapon was introduced. The laser protection technique including passive protection and active protection was analyzed, and the advantage and disadvantage of each protection technique were compared. An example was demonstrated in order to evaluate protection efficiency which the different waveband laser was analyzed within field and outside field. The result shows that the laser within field and waveband is most fatal. The optical payload can be disturbed even when the passive protection technique is adopted. Lastly, the suggestion of laser protection was presented.Accession Number: 20114414481713 -
Record 68 of
Title:Measurement of focal spot centroid based on image processing
Author(s):Xia, Ai-Li(1); Ma, Cai-Wen(1)Source: Guangdianzi Jiguang/Journal of Optoelectronics Laser Volume: 22 Issue: 10 DOI: Published: October 2011Abstract:A new method for enhancing the detection accuracy of the centroid of focal spot is put forward based on the image procesing techniques. After the Hartmann-Shark (H-S) wavefront sensor gets a series of focal spot array images, the subaperture detection windows are optimized by the adaptive threshold method for the optimum matching between the detection windows and the corresponding focal spots distribution areas and then the linear interpolation is used in the detection windows for higher precision image which is more similar to the original image. Furthermore, the image noise in the detection window is smoothed, so the detection accuracy of the sensor is improved. The experimental results demonstrate that the precision, repeatability and stability of focal spot centroid measurement by the proposed method are better than the results obtained via the traditional centroid methods.Accession Number: 20114414481658 -
Record 69 of
Title:Development of low readout noise scientific CCD camera for lunar astronomical observation
Author(s):Ge, Wei(1); Gan, Yu-Quan(1); Wang, Hong(1); Xu, Guang-Zhou(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 8196 Issue: DOI: 10.1117/12.900695 Published: 2011Abstract:High sensitivity and SNR are requested in lunar astronomical observation in order to get dark and feeble objects. Scientific CCD Cameras used in lunar astronomical observation usually have following characteristics: high quantum efficiency, wide spectral response, good photometric linearity and wide dynamic range. However, extremely low readout noise is usually a key indicator of the camera. A CCD camera, based on E2V's back-illuminated ultraviolet-enhanced scientific grade AIMO image sensor, has been designed for lunar astronomical observation. Four major kinds of electrical optimal design are presented in order to reduce the readout noise of the camera. The experiment result shows that: in the 200K pix/s of the pixel clock, the camera system gain is 1.83e-/ADU, and the readout noise is less than 6e-. ? 2011 SPIE.Accession Number: 20113614296277 -
Record 70 of
Title:Parallel two-step phase-shifting point-diffraction interferometry for microscopy based on a pair of cube beamsplitters
Author(s):Gao, Peng(1,4); Yao, Baoli(1); Min, Junwei(1); Guo, Rongli(1); Zheng, Juanjuan(1); Ye, Tong(1); Harder, Irina(2); Nercissian, Vanusch(3); Mantel, Klaus(2)Source: Optics Express Volume: 19 Issue: 3 DOI: 10.1364/OE.19.001930 Published: January 31, 2011Abstract:Parallel two-step phase-shifting point-diffraction interferometry for microscopy based on a pair of cube beamsplitters is proposed. The first 45°-tilted cube beamsplitter splits object wave into two parallel copies: one copy is filtered by a pinhole in its Fourier plane to behave as reference wave, while the other one remains unchanged as object wave. The second cube beamsplitter combines the object and reference waves, and then split them together into two beams. Along with the two beams, two parallel phase-shifting interferograms are obtained in aid of polarization elements. Based on the proposed configuration, slightly-off-axis interferometry for microscopy is performed, which suppresses dc term by subtracting the two phase-shifting holograms from each other. The setup is highly stable due to its common-path configuration, and has been demonstrated to be suitable for measuring moving objects or dynamic processes. ? 2011 Optical Society of America.Accession Number: 20110713664230 -
Record 71 of
Title:Correction of CCD noise in light field distribution measurement
Author(s):Liu, Lili(1); Da, Zhengshang(1); Tian, Xinfeng(1); Duan, Yaxuan(1); Li, Dongjian(1); Sun, Ce(1); Dong, Xiaona(1)Source: Qiangjiguang Yu Lizishu/High Power Laser and Particle Beams Volume: 23 Issue: 9 DOI: 10.3788/HPLPB20112309.2346 Published: September 2011Abstract:To suppress the influences aroused by CCD noise in measuring laser near field distribution, the paper proposes a method to correct CCD noise using a priori knowledge of CCD noise and its observed value based on contrast test model. Compared with the existing method, this method can suppress the influences caused by CCD noise effectively, thus lowering measurement uncertainty and improving measurement confidence, and the extended uncertainty reduces from 0.6% to 0.3%.Accession Number: 20114614525175 -
Record 72 of
Title:Enhanced biologically inspired model for object recognition
Author(s):Huang, Yongzhen(1); Huang, Kaiqi(1); Tao, Dacheng(2); Tan, Tieniu(1); Li, Xuelong(3)Source: IEEE Transactions on Systems, Man, and Cybernetics, Part B: Cybernetics Volume: 41 Issue: 6 DOI: 10.1109/TSMCB.2011.2158418 Published: December 2011Abstract:The biologically inspired model (BIM) proposed by Serre presents a promising solution to object categorization. It emulates the process of object recognition in primates' visual cortex by constructing a set of scale- and position-tolerant features whose properties are similar to those of the cells along the ventral stream of visual cortex. However, BIM has potential to be further improved in two aspects: mismatch by dense input and randomly feature selection due to the feedforward framework. To solve or alleviate these limitations, we develop an enhanced BIM (EBIM) in terms of the following two aspects: 1) removing uninformative inputs by imposing sparsity constraints, 2) apply a feedback loop to middle level feature selection. Each aspect is motivated by relevant psychophysical research findings. To show the effectiveness of the EBIM, we apply it to object categorization and conduct empirical studies on four computer vision data sets. Experimental results demonstrate that the EBIM outperforms the BIM and is comparable to state-of-the-art approaches in terms of accuracy. Moreover, the new system is about 20 times faster than the BIM. ? 2006 IEEE.Accession Number: 20114814561190