Journals >Opto-Electronic Engineering
Contents
2009
Volume: 36 Issue 12
29 Article(s)
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Research Article
SSR Modified Unscented JPDA Tracking for Multisensor Asynchronous System
PENG Dong-liang, YE Jun-jun, and GUO Yun-fei
Aiming at the problem of variable sampling rate sensor multi-target tracking in clutter,considering the ability that Secondary Surveillance Radar(SSR) can identify enemy or friend target and enhance the accuracy of tracking enemy target,a SSR modified unscented Joint Probabilistic Data Association(JPDA) tracking algoriAiming at the problem of variable sampling rate sensor multi-target tracking in clutter,considering the ability that Secondary Surveillance Radar(SSR) can identify enemy or friend target and enhance the accuracy of tracking enemy target,a SSR modified unscented Joint Probabilistic Data Association(JPDA) tracking algorithm is proposed for multi-sensor asynchronous system. Firstly,by using asynchronous data dealing way of mapping measurements,point track of the multi-sensor measurements is composed. Secondly,SSR is used to modify the height information of the enemy target adaptively. Finally,by using the unscented JPDA algorithm,the sequential filtering fusion of asynchronous sampling measurements can be realized. The validity of this algorithm on the improvement of target tracking accuracy and correct associate probability is illustrated through Monte-Carlo simulations..
Opto-Electronic Engineering
- Publication Date: Oct. 09, 2021
- Vol. 36, Issue 12, 1 (2009)
Nonlinear Kalman Filter Method for Electro-optical Tracking
WANG Qiu-ping, ZHOU Yuan, and KANG Shun
In order to obtain the optimal minimum variance state estimation for electro-optical tracking,a nonlinear Kalman filter algorithm is provided by combining reduced state Kalman filter and first-order linear in nonlinear system,and the algorithm structure is summarized in detail. Then,it is applied in nonlinear measuremeIn order to obtain the optimal minimum variance state estimation for electro-optical tracking,a nonlinear Kalman filter algorithm is provided by combining reduced state Kalman filter and first-order linear in nonlinear system,and the algorithm structure is summarized in detail. Then,it is applied in nonlinear measurement electro-optical tracking system and compared the performances of reduced state Kalman filter with extended Kalman filter and unscented Kalman filter. The Matlab simulation results show that combining reduced state Kalman filter and first-order linear in nonlinear system is valid,and the performance outperforms the extended Kalman filter and unscented Kalman filter..
Opto-Electronic Engineering
- Publication Date: Oct. 09, 2021
- Vol. 36, Issue 12, 7 (2009)
Multi-target Detection Using Fractal Feature Fusion of Different Source Image
TAO Bing-jie, and WEI Yu-xing
As to the detection of multi-target,a feature-level fusion detection scheme which uses fractal feature of multi-source images is proposed. Firstly,the character of multi-target detection is analyzed,the fractal theory is introduced,and then the theory of fusion detection scheme is introduced in detail. Some targets areAs to the detection of multi-target,a feature-level fusion detection scheme which uses fractal feature of multi-source images is proposed. Firstly,the character of multi-target detection is analyzed,the fractal theory is introduced,and then the theory of fusion detection scheme is introduced in detail. Some targets are segmented in infrared image. Afterwards,using the statistic character can build up irregularity of fractal dimension,and areas are searched and signed in the visible light fractal dimension image,which has close fractal statistic feature to the target area detected. At last,the whole targets are successfully detected after clustering and recognition based on the rule of distance similarity degree. The experimental results show that the fusion detection scheme can detect and recognize target effectively..
Opto-Electronic Engineering
- Publication Date: Oct. 09, 2021
- Vol. 36, Issue 12, 11 (2009)
Target Extraction Based on Data Regrouping Algorithm
WEI Kun, JING Zhong-liang, JIANG Shou-shan, and XIAO Gang
It’s an important work to detect and locate targets in image. A new method,named Data Regrouping (DRG) algorithm,is proposed. This approach scans the image only once to record data related to targets,and transforms image process problem to data structure problem,thus complexity is reduced. The DRG method doesn’t need oIt’s an important work to detect and locate targets in image. A new method,named Data Regrouping (DRG) algorithm,is proposed. This approach scans the image only once to record data related to targets,and transforms image process problem to data structure problem,thus complexity is reduced. The DRG method doesn’t need overlaborate labeling and has nothing with repetitiveness. Using the infrared images of ground gathered by the sensor of our airborne testing system for heavy-weapon range test,we apply DRG algorithm to extract infrared small targets and achieve the goal of detecting and locating ground control points in real time. The experiment result shows that our method is accurate,reliable,and has great ability of anti-jamming and anti-noise..
Opto-Electronic Engineering
- Publication Date: Oct. 09, 2021
- Vol. 36, Issue 12, 16 (2009)
Exposure Time Optimization of the Star Sensor
SHEN Ben-jian, TAN Ji-chun, YANG Jian-kun, and LIAO Jia-li
Exposure time has effect on position accuracy of star sensor. In this paper,motion model of star spot which is combined with the effect of CCD noise has been established. The centroid accuracy of the star spot affected by sub-pixels arithmetic and CCD noise were analyzed at different exposure time with CCD47-20 chip,anExposure time has effect on position accuracy of star sensor. In this paper,motion model of star spot which is combined with the effect of CCD noise has been established. The centroid accuracy of the star spot affected by sub-pixels arithmetic and CCD noise were analyzed at different exposure time with CCD47-20 chip,and the optimum exposure time was calculated. The results show that the accuracy of arithmetic was degraded and the accuracy of star spot affected by CCD noise was decreased when the exposure time increased. The optimum exposure time is 200 ms when the motion rate is 4.67 pixels per second for a single star of 6.5 magnitude,and the star spot location accuracy is better than 1/50 pixel with 5×5 window..
Opto-Electronic Engineering
- Publication Date: Oct. 09, 2021
- Vol. 36, Issue 12, 22 (2009)
Analysis of Infrared Characteristics of Spatial Balloon
WU Xiao-di, LING Yong-shun, Lü Xiang-yin, YANG Hua, and HUANG Chao-chao
The perfect theoretical calculation models of the spatial balloon’s temperature field and IR radiant feature are built up. The space heat flux which the spatial balloon gets is calculated in the appropriate coordinate system. The surface temperature distribution of the balloon is gotten by solving the transient heat baThe perfect theoretical calculation models of the spatial balloon’s temperature field and IR radiant feature are built up. The space heat flux which the spatial balloon gets is calculated in the appropriate coordinate system. The surface temperature distribution of the balloon is gotten by solving the transient heat balance equations with the use of the finite element software,ANSYS 10.0. On the basis of the solved surface temperature distribution,taking the balloon as a point object,the spatial distribution of infrared radiation intensity in two IR bands is calculated. Finally,the differences of the surface temperature distribution and the infrared radiation intensity spatial distribution between the spatial balloon gotten in this paper and a spatial ballistic target gotten in our previous work are compared and analyzed in detail. The research results have referential value on infrared detecting and recognition of spatial targets..
Opto-Electronic Engineering
- Publication Date: Oct. 09, 2021
- Vol. 36, Issue 12, 27 (2009)
Quantitative Measurement of Ba and Mn in Soil by Laser Induced Breakdown Spectroscopy
CHEN Qiao-ling, ZHOU Wei-dong, YING Chao-fu, HUANG Ji-song, and LONG Jing-ming
The analysis of heavy metals in soil usually requires a complex procedure and digestion time if carried out by using traditional analytical techniques. In this paper,a moveable Laser-Induced Breakdown Spectroscopy (LIBS) instrument is established which is mainly equipped with a pulsed 1 064 nm Nd:YAG laser and a portabThe analysis of heavy metals in soil usually requires a complex procedure and digestion time if carried out by using traditional analytical techniques. In this paper,a moveable Laser-Induced Breakdown Spectroscopy (LIBS) instrument is established which is mainly equipped with a pulsed 1 064 nm Nd:YAG laser and a portable spectrometer,and has been applied for the quantitative measurement of Ba and Mn in soil. The intensity and relative standard deviations of the signal of Ba and Mn are carefully investigated by varying the way of data acquisition. Along with the experimental parameters optimization,a new data acquisition and processing method is used to improve the measurement precision and sensitivity. The calibration curves for quantitative measurement of Ba and Ma are derived. The measurement precisions,in terms of Relative Standard Deviations (RSD),are 9.0 % and 10.24% for Ba and Mn respectively. The Limits of Detection (LOD) for Ba and Mn in soil are improved to be 19.4 mg/kg and 115.4 mg/kg respectively,and are better than the results reported in literature..
Opto-Electronic Engineering
- Publication Date: Oct. 09, 2021
- Vol. 36, Issue 12, 33 (2009)
A Measurement Method for a CW Laser Modulation Spectrum Based on Optical Beat Frequency
ZHANG Rong-yan, FENG Yan-ying, YAN Shu-bin, XIONG Ji-jun, and REN Xiao-hong
Because of the limitation of the F-P interferometer for the analysis of a CW laser modulation spectrum,an optical beat frequency method is proposed,which can be used to measure the spectrum with a modulation frequency ~kHz. This method is based on the photoelectric conversion technique. We can get the beat frequency siBecause of the limitation of the F-P interferometer for the analysis of a CW laser modulation spectrum,an optical beat frequency method is proposed,which can be used to measure the spectrum with a modulation frequency ~kHz. This method is based on the photoelectric conversion technique. We can get the beat frequency signal of the reference laser and a CW modulation spectrum with the spectrum analyzer,and then have the relative electric field strength of the various optical frequency of a CW laser modulation spectrum through the corresponding mathematical calculation so as to realize the CW modulation spectrum analysis. After theoretically modeling,experiments were carried out to measure a CW laser modulation spectrum generated by a diode laser and an EOM device with the proposed method. Compared with the measuring results with F-P interferometer,experimental results show the feasibility of an optical beat frequency method..
Opto-Electronic Engineering
- Publication Date: Oct. 09, 2021
- Vol. 36, Issue 12, 37 (2009)
Simulation of Echo Signal in Laser Imaging Detection System
YAN Xiao-wei, DENG Jia-hao, and SUN Zhi-hui
The simulation and analysis of the laser pulse echo signal are very useful to study different kinds of echo signal processing approaches and produce 3-D laser simulated images for target. In this study,the uniform time propagation and spatial distribution models of the emitted laser pulse were built. The reflected signThe simulation and analysis of the laser pulse echo signal are very useful to study different kinds of echo signal processing approaches and produce 3-D laser simulated images for target. In this study,the uniform time propagation and spatial distribution models of the emitted laser pulse were built. The reflected signal from the laser pulse sent at the laser imaging simulation template arising from 3-D target model could be calculated as a convolution sum between the impulse responses and the emitted pulses for the subareas in the laser footprint. The simulation analyses show that the ranging error caused by the simulation approximations is minor,and the better simulation precision of the echo signal is achieved in coordination with high simulation efficiency by adjusting the number of the subarea in the laser footprint..
Opto-Electronic Engineering
- Publication Date: Oct. 09, 2021
- Vol. 36, Issue 12, 42 (2009)
High Reflectivity Measurement of Mid-and-far Infrared Mirrors with a Quantum Cascade Laser
ZHAO Tong-kai, HAN Yan-ling, and QU Zhe-chao
The reflectivity measurement on high reflective mirrors in the mid-and-far infrared range was performed based on the Cavity Ring-down (CRD) technique. A pulsed quantum cascade laser with center wavelength of 9.7μm was used as the light source in the experimental setup,with which the reflectivity of the cavity mirrors aThe reflectivity measurement on high reflective mirrors in the mid-and-far infrared range was performed based on the Cavity Ring-down (CRD) technique. A pulsed quantum cascade laser with center wavelength of 9.7μm was used as the light source in the experimental setup,with which the reflectivity of the cavity mirrors at different cavity lengths was measured. The reflectivity was determined statistically to be 99.946 4% and the measured repeatability error is better than ±0.001 4%. The experimental results indicated that the CRD setup has a high repeatability and accuracy,and can be applied in high reflectivity measurements of mid-and-far infrared mirrors..
Opto-Electronic Engineering
- Publication Date: Oct. 09, 2021
- Vol. 36, Issue 12, 47 (2009)
Fluorescence Detection System for Benzoylurea Pesticides Based on Charge-coupled Device
WANG Yu-tian, XU Hui-juan, WANG Shu-tao, and WANG Zhong-dong
According to spectral characteristics that benzoylurea pesticides can emit fluorescence as they are irradiated by UV rays,an optical fiber fluorescence measurement system based on Charge-coupled Device (CCD) was designed for pesticides residue. The system adopted a pulsed xenon lamp as excitation light-source,employed According to spectral characteristics that benzoylurea pesticides can emit fluorescence as they are irradiated by UV rays,an optical fiber fluorescence measurement system based on Charge-coupled Device (CCD) was designed for pesticides residue. The system adopted a pulsed xenon lamp as excitation light-source,employed optical fibers to transmit and detect fluorescence,and used linear-array CCD instead of traditional photomultiplier tube as photoelectric detection device of the fluorescence signal. Moreover,it was equipped with high-speed A/D data acquisition card,implemented photoelectric conversion of the fluorescence and data acquisition under the control of a singlechip,and further achieved the concentration measurement of flufenoxuron and hexaflumuron. The result indicates that,when the excitation wavelength is 290 nm for flufenoxuron and 345 nm for hexaflumuron respectively,the fluorescence intensity of the former appears maximum as the wavelength is 360 nm and that of the latter appears maximum as the wavelength is 418 nm. The minimum detecting limits are 12 μg/L and 20 μg/L respectively. The fluorescence intensity is directly proportional to solution concentration in the range of 25~1 000 μg/L. This measurement system has several characteristics such as high sensitivity and wide linear range,which can meet the demand of fluorescence detection..
Opto-Electronic Engineering
- Publication Date: Oct. 09, 2021
- Vol. 36, Issue 12, 51 (2009)
Analysis and Design of Structure Parameters of Vision Measuring Sensor System
WU Zhang-liang, SUN Chang-ku, and YANG Zhong-dong
Parameter models of two typical coordinate measuring systems of a line-structured light visual sensor and a symmetrical binocular visual sensor are investigated with the trigonometric method. By analyzing the relations between the coordinate measuring models and the structural parameters of the two typical visual sensoParameter models of two typical coordinate measuring systems of a line-structured light visual sensor and a symmetrical binocular visual sensor are investigated with the trigonometric method. By analyzing the relations between the coordinate measuring models and the structural parameters of the two typical visual sensor systems,the effect of the visual sensor structural parameters and their calibration errors on the sensor measurement result is investigated. The error analysis explicitly illustrates the dependence of the visual sensor accuracy on the sensor structural parameters. Lastly,based on the comprehensive consideration for designing an ideal visual sensor,the optimum rules of structural parameters are proposed,and the design methods of the two typical sensors are derived..
Opto-Electronic Engineering
- Publication Date: Oct. 09, 2021
- Vol. 36, Issue 12, 56 (2009)
Precision Study and Application of Light Centroid Method in Measurement of Optical Fibers Position
GU Yong-gang, ZHAI Chao, JIN Yi, and CHU Jia-ru
In order to ensure that the Large Sky Area Multi-Object Fiber Spectroscopy Telescope (LAMOST) system can run accurately,it is necessary to measure the position of optical fibers on the focal plate of LAMOST. From the view of practical applications,the detection precision of light centroid method is introduced. ConnecteIn order to ensure that the Large Sky Area Multi-Object Fiber Spectroscopy Telescope (LAMOST) system can run accurately,it is necessary to measure the position of optical fibers on the focal plate of LAMOST. From the view of practical applications,the detection precision of light centroid method is introduced. Connected with a variety of experiments based on the theoretical analysis,the measuring conditions,such as the light spot size,the camera aperture and the light intensity on the end of fibers,were detailedly studied and their relationships to the precision of light centroid method were specifically analyzed. In addition,the centroid movement caused by change of light intensity was revealed. Finally,according to the result of experiments,the best detection conditions are provided for the factual measurement..
Opto-Electronic Engineering
- Publication Date: Oct. 09, 2021
- Vol. 36, Issue 12, 62 (2009)
Measurement Technology of Surface Flow Velocity for Hydraulic Physical Model
WU Jun, CHEN Wei-min, and DING Shen-qi
Aiming at the technology actuality of surface flow velocity measurement,a novel noncontact method for measuring surface flow velocity is proposed. Principle of flow measurement is deduced,and the factors that affect measurement accuracy are analyzed. Experimental system is set up. In the cases of three sediment concentAiming at the technology actuality of surface flow velocity measurement,a novel noncontact method for measuring surface flow velocity is proposed. Principle of flow measurement is deduced,and the factors that affect measurement accuracy are analyzed. Experimental system is set up. In the cases of three sediment concentrations,flow velocity is measured at 6 different flow rates. The experimental results show that under three different sediment concentrations,the measured flow velocity accords very well with the calibration flow velocity,which proves the feasibility of the theory. It is found that the relative error can be controlled less than 8% under the circumstances of suitable sediment in liquid..
Opto-Electronic Engineering
- Publication Date: Oct. 09, 2021
- Vol. 36, Issue 12, 68 (2009)
Calibration Method for Rudders Angular Displacement Based on Monocular Vision
HE Sen, WANG Zhi-bin, ZHANG Xu-feng, GAO Yong-quan, and CAO Mei-zhen
Three circle centers are taken as chief mark of the target-plane. These circles are taken as auxiliary mark. The circle center is marked by the intersection of two lines. The diameter parallel to the image-plane is taken as characteristic diameter,by which the depth information for the target plane can be got from elliThree circle centers are taken as chief mark of the target-plane. These circles are taken as auxiliary mark. The circle center is marked by the intersection of two lines. The diameter parallel to the image-plane is taken as characteristic diameter,by which the depth information for the target plane can be got from elliptic figures on the image-plane easily,so the solution of the inverse-perspective-transformation can be made simple and accurate. By designing a sub-pixel processing,circler-centre-image position and characteristic diameter image length can be got exactly. An algorithm was designed to calculate circle centre position. Then plane formula of the target plane can be got. The rudder’s angular displacement can be expressed by the target’s angular displacement. The computer simulating test indicates that measurement error for circle center image position within 0.02 pixels and measurement error for angular displacement within 0.005°. The measurement error caused by the target plane deviation from the direction parallel with the rudder-axis can be corrected in time. By this method,the angular displacement of aileron,flop,elevator and rudder of the airplane may be calibrated..
Opto-Electronic Engineering
- Publication Date: Oct. 09, 2021
- Vol. 36, Issue 12, 73 (2009)
Realization and Performance Analysis of PMD Compensation Based on DOP Detection
CHEN Ying, ZHU Qi-guang, and LI Zhi-quan
To avoid the limitation of Polarization Mode Dispersion (PMD) to the long-distance and high-rate optical fiber communication system,a dynamic adaptive PMD compensation system based on Degree of Polarization (DOP) was designed. According to the relationship between DOP and Differential Group Delay (DGD),the optimum valuTo avoid the limitation of Polarization Mode Dispersion (PMD) to the long-distance and high-rate optical fiber communication system,a dynamic adaptive PMD compensation system based on Degree of Polarization (DOP) was designed. According to the relationship between DOP and Differential Group Delay (DGD),the optimum value was searched and tracked by the control algorithm,and the value of PMD and its compensation effect could be reflected by DOP. Through adjusting the angle of waveplates in the polarization controller and the length of the variable delay line,the two principal states of polarization were adjusted to optimize DOP,and a close-loop compensation system was established. It was demonstrated from the experimental results that the worsening signal waveform was resumed effectively,and the opening of the eye diagram was improved obviously. The response time of the compensation system was about 110ms,and the Bit Error Rate (BER) was 3.59e-16,which satisfied the requirement for BER in the transmission system..
Opto-Electronic Engineering
- Publication Date: Oct. 09, 2021
- Vol. 36, Issue 12, 79 (2009)
A Scheme of Polarization Mode Dispersion Partial Compensation in 60 km Installed Fiber Cable Links
TAO Ning, ZHANG Li-yong, and WU Xing-kun
Polarization Mode Dispersion (PMD) has become a dominate limiting factor in 40 Gb/s and higher speed fiber-optics communication systems. In order to make the PMD compensation scheme cost-effective and easy to install in practical communication fiber paths,a PMD partial compensation scheme based on two-stage fixed delayPolarization Mode Dispersion (PMD) has become a dominate limiting factor in 40 Gb/s and higher speed fiber-optics communication systems. In order to make the PMD compensation scheme cost-effective and easy to install in practical communication fiber paths,a PMD partial compensation scheme based on two-stage fixed delay structure was designed,fabricated and tested in practical underground fiber links. The performance of this scheme was examined by using optical communication system simulation software Optisystem 3.0,and parameters of the compensator were optimized. Compensation experiment for four 60 km-long installed fiber cable links was in a good agreement with the simulated result,with a 15～20% of PMD compensation achieved..
Opto-Electronic Engineering
- Publication Date: Oct. 09, 2021
- Vol. 36, Issue 12, 84 (2009)
Digital Watermarking Technique Based on Digital Holography and Discrete Cosine Transform
YANG Tao, XU Jian-feng, YANG Guo-guang, and BAI Jian
The digital watermark technique is proposed based on Fresnel hologram and Discrete Cosine Transform (DCT). The Fresnel hologram of the original watermark is gotten by use of digital holography technique. Then the hologram is embedded in the median-frequency coefficients in the DCT domain. The position of watermark and The digital watermark technique is proposed based on Fresnel hologram and Discrete Cosine Transform (DCT). The Fresnel hologram of the original watermark is gotten by use of digital holography technique. Then the hologram is embedded in the median-frequency coefficients in the DCT domain. The position of watermark and geometric parameters of optical system are adopted to retrieve the watermark without the original host image. The algorithm has high security and practical value. Numerical experiments show that the embedded watermark is robust to usual image manipulations,such as superposing noise,cropping,filtering and lossy compression. Therefore,there is an application prospect for the algorithm..
Opto-Electronic Engineering
- Publication Date: Oct. 09, 2021
- Vol. 36, Issue 12, 91 (2009)
Non-subsampled Contourlet Transform Texture Image Retrieval System
CHEN Xin-wu, and GUO Jian-tao
Referring to the low retrieval rate of basic contourlet transform,a Non-subsampled Contourlet Transform (NSCT) texture image retrieval system is proposed. In the system,the contourlet transform is constructed by non-subsampled Laplacian pyramid and non-subsampled directional filter banks,sub-bands energy and standard dReferring to the low retrieval rate of basic contourlet transform,a Non-subsampled Contourlet Transform (NSCT) texture image retrieval system is proposed. In the system,the contourlet transform is constructed by non-subsampled Laplacian pyramid and non-subsampled directional filter banks,sub-bands energy and standard deviations are cascaded to form feature vectors,and the similarity metric is Canberra distance. Experimental results show that NSCT image retrieval system is superior to that of the original contourlet transform under the same system structure with almost the same length of feature vectors,retrieval time and memory needed. Moreover,NSCT decomposition structural parameters and image type can make significant effects on average retrieval rates..
Opto-Electronic Engineering
- Publication Date: Oct. 09, 2021
- Vol. 36, Issue 12, 97 (2009)
Suppressing Eyelash Interference Based on Morphological Operator
TANG Rong-nian, WENG Shao-jie, HAN Jiu-qiang, and ZHANG Xin-man
In order to improve the performance of eyelash interference suppressing algorithm in iris recognition method,a new algorithm based on Morphological operators was developed. Considering the eyelash as the fine nondirectional silt in the background of eye image,the suppression of eyelash interference can be taken as a prIn order to improve the performance of eyelash interference suppressing algorithm in iris recognition method,a new algorithm based on Morphological operators was developed. Considering the eyelash as the fine nondirectional silt in the background of eye image,the suppression of eyelash interference can be taken as a process to fill up these fine slits by using dilation operator. Compared with Gaussian filter algorithm,the proposed algorithm can suppress more eyelash interference,and has better performance. The experiment results from the CASIA iris database show that the proposed method can reduce more 40% eyelash pixels than that of the Gaussian filter algorithm. Using the proposed method,the accuracy of the Daugman’s algorithm and Wildes’ algorithm,which are traditional iris location algorithm,are improved 1.7% and 2% respectively,and the location time are decreased by 27.9% and 24.2% respectively..
Opto-Electronic Engineering
- Publication Date: Oct. 09, 2021
- Vol. 36, Issue 12, 103 (2009)
Multi-ellipse Detection Based on the Connected Convex Curve Searching
LI Xiao-min, WANG Yuan-yuan, and YU Jin-hua
In the multi-ellipse detection especially when they are overlapped,the existing methods such as the Randomized Hough Transform,show drawbacks of poor stability and low accuracy. In this paper,a new methodology was proposed based on the connected convex curve searching and ellipse fitting. Firstly,the edge curve is clusIn the multi-ellipse detection especially when they are overlapped,the existing methods such as the Randomized Hough Transform,show drawbacks of poor stability and low accuracy. In this paper,a new methodology was proposed based on the connected convex curve searching and ellipse fitting. Firstly,the edge curve is clustered into different groups by the convexity—leading to each group belonging to a certain ellipse. Secondly,the ellipse fitting is performed on grouped curves. Finally,curves on the same ellipse are merged. Since our method can make full use of properties of ellipse curves,it works well in experiments of both synthetic images and real-word images with a higher accuracy and a certain anti-noise performance..
Opto-Electronic Engineering
- Publication Date: Oct. 09, 2021
- Vol. 36, Issue 12, 107 (2009)
Application of Digital Image Processing in Measurement of Lenses’ Power Using MDT
WANG Qin, ZHAO Yu-huan, and YU Jing-chi
From principle of the measurement of lenses’ power using Moiré Deflection Technology (MDT),formula of the relationship between moiré fringes’ tilt angle and lenses’ power was presented. After a series of experimental study,moiré fringes of the test lenses were obtained. Meanwhile,based on the character oFrom principle of the measurement of lenses’ power using Moiré Deflection Technology (MDT),formula of the relationship between moiré fringes’ tilt angle and lenses’ power was presented. After a series of experimental study,moiré fringes of the test lenses were obtained. Meanwhile,based on the character of moiré fringes,appropriate digital image processing such as gray scale equality,image enhancement,image thinning etc. was done,and distinct skeleton lines of the moiré fringes were provided. In the end,through proper data processing,measuring results of different lenses’ power were given,and they were compared with the measuring results tested by focimeter. Results show that adopting proper digital image processing methods for measurement of lenses’ power using moiré deflection technology has high precision..
Opto-Electronic Engineering
- Publication Date: Oct. 09, 2021
- Vol. 36, Issue 12, 114 (2009)
A Judging Method of GPS Spoofing Interference
CHEN Bi-ran, and XU Bin
Based on the output C/N0 data of GPS OEM in NMEA0183 GSV format,fuzzy cluster method is used to differentiate out spoofed satellites and normal ones according to the different C/N0 values between spoofed satellites and normal ones. The result shows that this method can find spoofed satellites in high accuracy and the aBased on the output C/N0 data of GPS OEM in NMEA0183 GSV format,fuzzy cluster method is used to differentiate out spoofed satellites and normal ones according to the different C/N0 values between spoofed satellites and normal ones. The result shows that this method can find spoofed satellites in high accuracy and the algorithm is simple. It provides a new approach to judge GPS spoofing interference..
Opto-Electronic Engineering
- Publication Date: Oct. 09, 2021
- Vol. 36, Issue 12, 119 (2009)
Experimental Investigation of Stressed Mirror Polishing on Paraboloid
SUN Tian-xiang, YANG Li, WU Yong-qian, WAN Yong-jian, and FAN Bin
Fabrication of large aspheric mirror continues to be a challenge in the research field about advanced optical manufacture. Some advanced optics manufacturing research,which focused on large aspheric mirror manufactured by Stressed Mirror Polishing (SMP),is developed. SMP based on mechanics of elasticity is a novel asphFabrication of large aspheric mirror continues to be a challenge in the research field about advanced optical manufacture. Some advanced optics manufacturing research,which focused on large aspheric mirror manufactured by Stressed Mirror Polishing (SMP),is developed. SMP based on mechanics of elasticity is a novel aspheric fabrication technology that could transform aspheric optical fabrication technology into sphere optical fabrication technology,which greatly improve the fabrication efficiency. Take fabricating a paraboloid mirror of Φ314 mm diameter and F/7 for example to analyze the optical fabrication technology progress of paraboloid in stressed-state. Rationality and effectiveness of SMP were investigated. Establishing measurement system of sphere and paraboloid to analyze the experiment result and adopting interferometer to get surface shape of finished paraboloid,PV=3.317λ,rms=0.489λ. The results indicate that the method of the SMP can be used to produce the revolution axisymmetric paraboloid mirrors with high precision and efficiency..
Opto-Electronic Engineering
- Publication Date: Oct. 09, 2021
- Vol. 36, Issue 12, 123 (2009)
Optimization Design of Top Contact Metallization of Concentrator Solar Cells
HUANG Sheng-rong, LIN Gui-jiang, WU Jyh-chiarng, and HUANG Mei-chun
An optimum grid pattern of the concentrator solar cell top contact metallization was designed. Several power-loss mechanisms of the smallest element were analyzed detailedly. The optimum grid spacing recursion formula was deduced. The optimum grid spacing and the power-loss for the grids of different width were calculaAn optimum grid pattern of the concentrator solar cell top contact metallization was designed. Several power-loss mechanisms of the smallest element were analyzed detailedly. The optimum grid spacing recursion formula was deduced. The optimum grid spacing and the power-loss for the grids of different width were calculated. The shadowing loss was the biggest loss when the grid spacing was narrower than the optimum one if ohmic contact was very well. Otherwise,the current transporting power losses of the grid and solar cell material became the main reason. For the high concentrator solar cell,the thickness of the grid was proposed to be designed more thickly. The results of calculation and analysis can be used in the designing concentrator solar cells..
Opto-Electronic Engineering
- Publication Date: Oct. 09, 2021
- Vol. 36, Issue 12, 127 (2009)
Temperature Test and Error Compensation of FOG
LI Jia-lei, HE Jing, and XU Hua-long
The temperature and nonlinear characteristics of Fiber Optic Gyro (FOG) are analyzed,and position and angular velocity experiments are carried out based on the temperature test system,so the effects of different temperature and angular velocity on FOG’s output can be studied. According to experimental results,temperatuThe temperature and nonlinear characteristics of Fiber Optic Gyro (FOG) are analyzed,and position and angular velocity experiments are carried out based on the temperature test system,so the effects of different temperature and angular velocity on FOG’s output can be studied. According to experimental results,temperature error model of zero bias and temperature and nonlinear error model of scale factor of FOG are built,whose parameters are estimated by using least square method. Through simulation,it is proved that the built models can reflect the temperature and nonlinear characteristics of FOG very well. Then the compensation can be done based on the models,and the accuracy of FOG can be improved greatly..
Opto-Electronic Engineering
- Publication Date: Oct. 09, 2021
- Vol. 36, Issue 12, 132 (2009)
Embedded Technology of High-speed Image Storage Based on SSD
TIAN Yuan, REN Guo-qiang, and WU Qin-zhang
One of the most significant technologies in digital image processing is storage of image data with high speed and high capacity. In order to implement real-time and high-speed image data storage,a method with Solid State Disk (SSD) on embedded Linux system was provided in this paper. Linux driver was used to manage SASOne of the most significant technologies in digital image processing is storage of image data with high speed and high capacity. In order to implement real-time and high-speed image data storage,a method with Solid State Disk (SSD) on embedded Linux system was provided in this paper. Linux driver was used to manage SAS controller and image data was stored in SSD with high-speed. The architectures of software were introduced. Linux driver was provided with details. The factors of influencing storage speed were analyzed. The experimenta1 results indicate that the image data storage speed can achieve 150 MB/s. It can satisfy the requirements of high-speed image data storage of high frame frequency camera..
Opto-Electronic Engineering
- Publication Date: Oct. 09, 2021
- Vol. 36, Issue 12, 138 (2009)
Freeform Reflector Design for Street Uniform Illumination
WANG Hong, ZHANG Qi-hui, ZHANG Xiao-fan, and WANG Hai-hong
According to the radiation characteristics of LED light sources and lighting requirements of illumination distribution,the energy of LED light source is distributed by using grid method,which corresponds with the small energy blocks in the target plane. We can establish the corresponding relationship between the angle According to the radiation characteristics of LED light sources and lighting requirements of illumination distribution,the energy of LED light source is distributed by using grid method,which corresponds with the small energy blocks in the target plane. We can establish the corresponding relationship between the angle of the light exit from LED light source and the coordinates of point in the target plane. According to the corresponding relationship,calculate the free-form reflector points,and by mechanical modeling software,fit the points to surface entity and import the entity into optical simulation software to carry out the simulation. The results illustrate that through the role of reflector cup on the LED,we can get a uniform rectangular facula in the target surface..
Opto-Electronic Engineering
- Publication Date: Oct. 09, 2021
- Vol. 36, Issue 12, 143 (2009)
Multi-channel Image Data of CCD Real-time Record System
QI Chun-dong, CHEN Liang, and ZENG Tao
In order to solve the real-time record and preprocessing problem of the multi-channel CCD image data,a scheme based on parallel Digital Signal Processing (DSP) technology is proposed,and the realization of the record system are described. The smallest system is mainly composed of four DSP chips and a general CPU,which In order to solve the real-time record and preprocessing problem of the multi-channel CCD image data,a scheme based on parallel Digital Signal Processing (DSP) technology is proposed,and the realization of the record system are described. The smallest system is mainly composed of four DSP chips and a general CPU,which can be used to record the image data of CCD with 6 channels in real time and separate the image data from the input data. Processing results can be recorded in the local disk or can be transmitted by Ethernet. Two or more systems can parallel process together when the input channels are more than 6 channels. The smallest system can achieve a high speed of 63.2 MB/s. This system has been succeeded in applying to a CCD image data acquisition with 18 channels..
Opto-Electronic Engineering
- Publication Date: Oct. 09, 2021
- Vol. 36, Issue 12, 147 (2009)
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