Journals >Infrared and Laser Engineering
Contents
2017
Volume: 46 Issue 5
34 Article(s)
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Ultrafast nonlinear refractive effect and mechanism of solvent nitrobenzene
Song Yinglin, and Li Zhongguo
The third-order nonlinear refractive index n2 of nitrobenzene liquid was studied using Z-scan technique under femtosecond and picosecond laser pulses. The Z-scan results demonstrate that the n2 value under 20 ps, 532 nm laser pulse excitation is 11 times larger than that under 300 fs, 800 nm excitation. The mechanism oThe third-order nonlinear refractive index n2 of nitrobenzene liquid was studied using Z-scan technique under femtosecond and picosecond laser pulses. The Z-scan results demonstrate that the n2 value under 20 ps, 532 nm laser pulse excitation is 11 times larger than that under 300 fs, 800 nm excitation. The mechanism of nonlinear refraction dynamics of nitrobenzene was investigated using pump-probe with phase object technique under femtosecond pulses excitation. The nonlinear response function of nitrobenzene under ultrafast laser excitation was determined from the pump-probe experimental results. The target of the present work is to provide a reference for future work of integrated photonic device and nonlinear optical measurement based on solvent nitrobenzene..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 5, 502001 (2017)
Status and prospect of target tracking based on deep learning
Luo Haibo, Xu Lingyun, Hui Bin, and Chang Zheng
The inverse synthetic aperture lidar(ISAL) have attracted increasing attention for its merits including small visual tracking which is considered as one of the important research topics in the field of computer vision due to its key role in versatile applications, such as precision guidance, intelligent video surveillaThe inverse synthetic aperture lidar(ISAL) have attracted increasing attention for its merits including small visual tracking which is considered as one of the important research topics in the field of computer vision due to its key role in versatile applications, such as precision guidance, intelligent video surveillance, human-computer interaction, robot navigation and public safety. The basic idea for implementing visual tracking is composed of finding the target object in a video or sequence of images, then determining its exact position in the next successive frames and finally generating the corresponding trajectory of this object. Visual tracking, however, is still a challenging problem in practice while taking into account the abrupt appearance changes of the target objects induced by their non-rigid transformation, the sophisticated lighting variation, the obstruction by the block or similar objects in the background and the camera jitter. Motivated by the successful applications in target detection and recognition in recent years, plenty of deep learning models have been integrated in the visual tracking and better performance over traditional methods was achieved in a series of data evaluations, which opens a new door in the field of visual tracking. In this paper, the overview and progress on visual tracking were summarized. The current challenges and corresponding solving approaches in this field are introduced firstly and in particular, several novel and mainstream visual tracking algorithms based on the deep learning are specially described and analyzed in details, including their basic ideas, advantages and disadvantages and future prospect..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 5, 502002 (2017)
[in Chinese]
Hyperspectral adaptive band selection method through nonlinear transform and information adjacency correlation
Zhang Aiwu, Du Nan, Kang Xiaoyan, and Guo Chaofan
Through nonlinear functional transform of hyperspectral remote sensing data, the modified Pearson correlation analysis can effectively identify comprehensive correlation coefficient(rcl), correlation type, and statistical significance level between spectrums. In this paper, nonlinear correlation the main correlation reThrough nonlinear functional transform of hyperspectral remote sensing data, the modified Pearson correlation analysis can effectively identify comprehensive correlation coefficient(rcl), correlation type, and statistical significance level between spectrums. In this paper, nonlinear correlation the main correlation relationship type between hyperspectral bands was proved. Based on correlation coefficient, the adjacent bands′ correlation coefficient(rac) of adaptive band selection(ABS) is to express band independence, but rac of ABS algorithm cannot effectively express such independence. Herein, a kind of information adjacency/equivalent bands′ correlation coefficient(riac), and via this index, the modified ABS(MABS) were proposed. Using public data and collected private data, the experiments of ABS, MABS(rl) based on linear correlation coefficient(rl), and MABS(rcl) based on rcl were carried out. These two case studies demonstrate that MABS is superior to ABS on spectral range, algorithm validity and accuracy. MABS can take both large amount of information and strong independence into consideration effectively. The spectral range of MABS′s bands selection result is more than ABS′s obviously, and MABS(rcl)′s is a little more than MABS(rl)′s. The ranking both overall classification accuracy and Kappa coefficient of those three kinds of algorithms are MABS(rcl)>MABS(rl)>ABS..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 5, 538001 (2017)
Design and implementation of CCD imaging circuit for airborne ultraviolet DOAS imaging spectrometer
Qiu Xiaohan, Wang Yu, Chang Zhen, Tian Yuze, and Si Fuqi
Airborne ultraviolet imaging DOAS(Differential Optical Absorption Spectroscopy) spectrometer monitors the distribution and changes of atmospheric trace gases by obtaining the UV radiation of atmosphere and surface reflection or scattering. In this spectrometer, the CCD imaging circuit is the core of electronic device. Airborne ultraviolet imaging DOAS(Differential Optical Absorption Spectroscopy) spectrometer monitors the distribution and changes of atmospheric trace gases by obtaining the UV radiation of atmosphere and surface reflection or scattering. In this spectrometer, the CCD imaging circuit is the core of electronic device. A complete system was designed and implemented by using frame transfer area array CCD-47-20. Field-Programmable Gate Array(FPGA) was adopted as the core controller of the CCD imaging circuit, which generated CCD driving sequences, CCD data acquisition, received and converted CCD analog imaging signal to digital signal. CCD digital imaging signal was drove by differential line driver and then acquired by the airborne communication system in low voltage differential signaling (LVDS) format. The design and implementation of the circuit was described, and the design process of the CCD imaging circuit was mainly discussed. The imaging resolution of airborne ultraviolet imaging DOAS spectrometer monitoring is 0.286°. The experiments show that the requirements of polluting gases observation can be satisfied..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 5, 538002 (2017)
[in Chinese]
Study of pose estimation based on multiple feature points topological determination
Wang Peng, Zhou Quantong, and Sun Changku
In monocular vision pose estimation, the topological relationship between objective feature points and image feature points where there are multiple feature points is difficult to determine. An algorithm based on multiple feature points topological determination was proposed to solve this problem where the correspondenIn monocular vision pose estimation, the topological relationship between objective feature points and image feature points where there are multiple feature points is difficult to determine. An algorithm based on multiple feature points topological determination was proposed to solve this problem where the correspondences are unknown. By mounting multiple feature points on the object, enough proper feature points for pose computing were guaranteed when the object is large-scale moving, which can improve the precision of pose estimation. The algorithm nested the iteration process of topological determination and the iteration process of pose computing into one iteration loop, solving them simultaneously. The pose estimation iteration process was based on para-perspective projection model, where the coordination of the projection of the object gravity center used as the initial parameter of iteration is not needed. The iteration process of topological determination was transformed into a solution of assignment problem. Each topological determination can obtain a better pose estimation in every pose estimation iteration loop. The results of multiple poses experiment and precision comparison experiment prove that the algorithm is qualified for the high precision pose estimation of 3D object with large scale motion, with the root mean square error 0.272° in the range of -120°-120°..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 5, 517001 (2017)
Star tracker accuracy analysis of PuJiang Satellite-1 in orbit
Mao Xiaonan, Zhou Qi, Ma Yingchao, Yan Xiaojun, Wei Lesi, Yu Luwei, Yin Haining, and Zhang Qing
For the evaluation of star tracker accuracy on board, a method was proposed using differenced quaternion, sliding window and optical axis included angle to analyse noise equivalent angle, total error of star trackers respectively, based on several kinds of data download from PuJiang Satellite-1 on board. The on board tFor the evaluation of star tracker accuracy on board, a method was proposed using differenced quaternion, sliding window and optical axis included angle to analyse noise equivalent angle, total error of star trackers respectively, based on several kinds of data download from PuJiang Satellite-1 on board. The on board test result shows the optical axis direction accuracy of the star tracker reached 15″ (3σ), meeting the requirement of AOCS, and the three-axis stability reached 0.01°. The method can be used for star tracker accuracy evaluation on board or real sky experiment on ground..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 5, 517002 (2017)
Calibration of optical axis parallelism by using star for astronomical observation system
Wang Yang, Huang Yu, Li Zhanfeng, and Wang Shurong
To satisfy the requirement of field measurement of optical axis parallelism for the ground-based astronomical observation system, a high-precision multi-optical axis parallel calibration system was put forward. For astronomical observation system which contains the imaging spectrometer, a star was used as a point sourcTo satisfy the requirement of field measurement of optical axis parallelism for the ground-based astronomical observation system, a high-precision multi-optical axis parallel calibration system was put forward. For astronomical observation system which contains the imaging spectrometer, a star was used as a point source, and the star image and its spectrum was synchronous acquisition by using the astronomy tracking system. It was not easy to determine the center of field of view in spectral dimension of the imaging spectrometer, and the scheme takes advantage of control system of the equatorial and a small field of view of the imaging spectrometer, so the center of field of view in spectral dimension was calculated by fitting energy of scanning the target star with respect to the scanning position, then the bias of optical axis parallelism between the instrument was calculated by Gaussian fitting. Experimental results show that the standard uncertainty of this measurement can reach 1.52″, and the optical measurement system structure is simple, so it meets the need of field optical axis parallel measurement with high precision and high speed between the imaging spectrometer and other imaging instrument..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 5, 517003 (2017)
Internal horizontal damping network of SAMS by applying adaptively adjustable damping ratio
Gu Pengfei, Wang Xingshu, Zheng Jiaxing, and Zhao Yingwei
In the autonomous navigation state, the periodic errors, such as the Schuler oscillation amplitude error, in the strap-down attitude measurement system(SAMS) can be restrained through the internal horizontal damping method. However, the schuler tuning condition of the SAMS will be destroyed when the damping network wasIn the autonomous navigation state, the periodic errors, such as the Schuler oscillation amplitude error, in the strap-down attitude measurement system(SAMS) can be restrained through the internal horizontal damping method. However, the schuler tuning condition of the SAMS will be destroyed when the damping network was introduced, and new attitude errors will be generated if the motion of the carrier changes quickly. In order to overcome the shortcomings of the conventional damping network with fixed damping ratio, a novel damping network with continuously adjustable damping ratio was designed to suppress the attitude error. The relationship between the acceleration of the carrier, the damping ratio and the attitude error was also derived. An adaptive-damping method was proposed to adjust the damping ratio of the system according to the carrier′s acceleration. The simulation results and experiment results indicate that the novel damping network can suppress the Schuler oscillation amplitude error, and the adaptive-damping method can reduce the ill effect of the damping network to the attitude estimation, and improve the performance of the SAMS..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 5, 517004 (2017)
Accurate real-time velocity measurement of photoelectric encoder based on wavelet transform
Du Yingcai, Song Lu, Wan Qiuhua, and Yang Shouwang
As a velocity feedback device, photoelectrical encoder was widely used in industry, aerospace, military and other fields. The precision and response influenced the whole system performance immediately. This paper studied velocity information arithmetic by using wavelet which reduced interference and noises. This arithmAs a velocity feedback device, photoelectrical encoder was widely used in industry, aerospace, military and other fields. The precision and response influenced the whole system performance immediately. This paper studied velocity information arithmetic by using wavelet which reduced interference and noises. This arithmetic had been applied in a space encoder, improved the dynamic response of control system, accuracy in steady-state. This arithmetic was simple, less resource, short time consuming and universal, can be extended to other encoder. Meanwhile, this paper designed velocity detection system, to achieve the detection of precision. The experiments shown that: the velocity error was reduced from 6.956 (")/ms to 0.370 7 (")/ms, by using this arithmetic..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 5, 517005 (2017)
Multi-point calibration method for division-of-amplitude photopolarimetric detection system
Wang Fangbin, Liu Tao, Hong Jin, Zhu Darong, and Xu Lu
Analytical accuracy of polarization remote sensing system is determined by instrumental detection performance. However, it is limited for the instrumental polarization introduced by various factors. In this paper, a multi-point calibration method for measurement matrix of division-of-amplitude (DoA) photopolarimetric dAnalytical accuracy of polarization remote sensing system is determined by instrumental detection performance. However, it is limited for the instrumental polarization introduced by various factors. In this paper, a multi-point calibration method for measurement matrix of division-of-amplitude (DoA) photopolarimetric detection system had been proposed by analyzing the measurement principle, and the conditions to calibrate a DoA polarization detection system with interval sampling polarization azimuth angle had been derived. Through building a test platform and conducting comparative experiments, the measuring matrix of aviation multi-angular polarimetric radiometer (AMPR) had been determined using the multi-point calibration method mentioned above and the uncertainty had been investigated. The experiment results indicate the measurement error of AMPR is less than 0.5% and corresponding uncertainty is also less than 0.5%, which demonstrate the detection system requirements has been met for AMPR and the feasibility of multi-point calibration method is verified.基金(2015QD04).
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 5, 517006 (2017)
[in Chinese]
Multi-objective topology optimization design and test for support structure of star sensor
Cheng Long, Wang Dong, Gu Song, Gao Fei, Yang Lin, and Li Lin
According to the special requirements of star sensor for micro satellite, combined with special working performance and environment of star sensor, multi-objective optimization design was carried out on the support structure of star sensor by using topological method, and finite element analysis and test were also doneAccording to the special requirements of star sensor for micro satellite, combined with special working performance and environment of star sensor, multi-objective optimization design was carried out on the support structure of star sensor by using topological method, and finite element analysis and test were also done. First, the basic theory of modal analysis and random vibration response were introduced in this paper. The expression formula of multi-objective topology optimization was derived. Second, the goal of optimization contains volume minimization of the support structure, and RMS value minimization of 4 installation point in the support structure where star sensor was installed. The topology optimization model of the support structure was established under the restriction of the lowest natural frequency. The topology optimization design was carried out by using OptiStruct software. Then, the modal analysis and random vibration response analysis of the optimized support structure were made by using finite element analysis software MSC.Patran&Nastran. The natural frequency was 327 Hz, the maximum amplification rate of the RMS value of the installation point was 0.55. Finally, the support structure was tested with the random vibration test. The test results are in good agreement with the finite element analysis results, and the maximum error is 0.07. The support structure of star sensor meets the requirements of the performance index for micro satellite..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 5, 520001 (2017)
Spatial resolution performance comparison of magnetic double-lens and single-lens framing tubes
Liao Yubo, Long Jinghua, Cai Houzhi, Lei Yunfei, and Liu Jinyuan
A large cathode framing tube was designed and developed based on the pulse-dilation technique. By virtue of Matlab programming, the spatial resolution of off-axis positions and the imaging distortion for magnetic double-lens and single-lens imaging were numerically simulated respectively. Resolution plates photoetched A large cathode framing tube was designed and developed based on the pulse-dilation technique. By virtue of Matlab programming, the spatial resolution of off-axis positions and the imaging distortion for magnetic double-lens and single-lens imaging were numerically simulated respectively. Resolution plates photoetched on the cathode micro-stripe were adopted to test the spatial performance of the tube. The experimental results show that at an imaging magnification of 2:1, the spatial resolution of the positions within 9 mm from the centre is higher than 5 lp/mm. Compared to magnetic single-lens imaging, the magnetic double-lens tube possesses a higher spatial resolution, a wider imaging range and a lower distortion, which provides a new way to improve the spatial resolving power of framing image converter tube..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 5, 520002 (2017)
[in Chinese]
Polarization splitter based on metal-decorated microstructure fiber
Yan Shibo, Lou Shuqin, Zhao Tongtong, and Zhang Junnan
A polarization splitter based on metal-decorated microstructure fiber was proposed. The relationship between splitter length and structure parameters was analyzed by using full vectorial finite element method. The variation rules of splitter length with hole pitch and duty ratio for the polarization splitter were obtaiA polarization splitter based on metal-decorated microstructure fiber was proposed. The relationship between splitter length and structure parameters was analyzed by using full vectorial finite element method. The variation rules of splitter length with hole pitch and duty ratio for the polarization splitter were obtained. Numerical results shows that the length of the polarization splitter decreases with the decrease of hole pitch and the ratio of hole diameter to hole pitch. Considering both the properties and the transmission loss caused by metal, a simple-structure polarization splitter based on metal-decorated microstructure fiber was optimized. The length of the polarization splitter is as short as 3.523 mm and the extinction ratio reaches up to 74.9 dB at the wavelength of 1.55 μm. The bandwidth is 40 nm from 1.53 μm to 1.57 μm where the extinction ratios are more than 20 dB covering the C band of optical communication. At the same time, when the length of polarization splitter exists ±5% error, it can also keep good performance..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 5, 522001 (2017)
[in Chinese]
Fabrication and optical responses of 2D Au nano array
Bai Zhengyuan, Zhang Long, and Wang Kangpeng
Ordered noble metal nanostructured arrays have attracted much attention due to their unique optical properties and flexible tuning abilities, which have shown promising applications in variety of micro/nano optoelectronic devices. Among the numerous research works, fast fabrication of Au periodic nanostructures in largOrdered noble metal nanostructured arrays have attracted much attention due to their unique optical properties and flexible tuning abilities, which have shown promising applications in variety of micro/nano optoelectronic devices. Among the numerous research works, fast fabrication of Au periodic nanostructures in large area is still one of the most popular issues. In this work, nanosphere self-assembling lithography techniques was employed for the fabrication of novel 2D Au nanostructure arrays with controlled Au particle sizes based on the monolayer periodic macroporous template. Moreover, the physical mechanism of the Au nanostructure formation was discussed in detail. The optical properties were investigated and the results clearly revealed the surface plasmon scattering and absorption properties of the Au nano array. Moreover, it was demonstrated with a remarkable two-photon absorption saturation effect for the 1 030 nm femtosecond pulses. The results imply the great potential of the Au nano arrays in many applications such as solar cell, optical switch and nano fabrication areas..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 5, 534001 (2017)
[in Chinese]
Large aperture lidar receiver optical system based on diffractive primary lens
Zhu Jinyi, and Xie Yongjun
Diffractive optical systems are promising in large aperture lidar receiver applications. The negative dispersion effect on lidar image quality caused by the diffractive primary lens was analyzed. Two chromatic aberration correcting methods, inserting high dispersion glass and adopting Schupmann theory, were discussed. Diffractive optical systems are promising in large aperture lidar receiver applications. The negative dispersion effect on lidar image quality caused by the diffractive primary lens was analyzed. Two chromatic aberration correcting methods, inserting high dispersion glass and adopting Schupmann theory, were discussed. An achromatic system based on Schupmann theory was lightweight, and provided perfect image quality. And the system light transmittance was over 60%. A design of lidar receiver optical system with 1m aperture and 1 mrad max FOV was demonstrated, and the system f/# was 8. The image quality attained diffraction limit approximately..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 5, 518001 (2017)
Design of the spontaneous deployable mechanism for space telescope based on lenticular tape springs
Zuo Yudi, Jin Guang, Xie Xiaoguang, Li Zongxuan, and Xie Peng
In order to reduce launch mass and volume of the space telescope apparently, and to make it suitable for the vehicle requirements of the microsatellite, a new spontaneous deployment mechanism of the space telescope based on the lenticular tape springs was designed, which aimed at one optical system. Firstly, the geometIn order to reduce launch mass and volume of the space telescope apparently, and to make it suitable for the vehicle requirements of the microsatellite, a new spontaneous deployment mechanism of the space telescope based on the lenticular tape springs was designed, which aimed at one optical system. Firstly, the geometrical sizes of the lenticular tape spring used in this article were preliminarily designated through theoretical analysis, and a new spontaneous deployment mechanism based on the lenticular tape springs was designed aimed at one space optical system. Secondly, the finite element model of the deployment mechanism was built, and its deployment characters were analyzed. Finally, the prototype of the spontaneous deployment mechanism was built up and the experiment was carried out to study its characters. Experimental results indicate that the deployment mechanism is 500 mm in height when it has deployed, and the repetitive deploy accuracy of it can be reached much less than 0.1 mm, also, the fundamental frequency is about 35.5 Hz when it has deployed. It can satisfy the deployment mechanism′s requirements of simple structure, low mass, steady and reliable deployment, as well as higher precision for space telescope..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 5, 518002 (2017)
Design of diffractive-refractive dual-band co-path parfocal optical system
Gao Ming, Xu Huangrong, Liu Jun, Lv Hong, and Chen Yang
In order to improve the imaging performance of dual-band optical system, considering the characteristics of visible light and MWIR, diffractive-refractive dual-band co-path and parfocal without compensation optical path optical system was designed. The four lens achromatic and focal length compensation expression betweIn order to improve the imaging performance of dual-band optical system, considering the characteristics of visible light and MWIR, diffractive-refractive dual-band co-path and parfocal without compensation optical path optical system was designed. The four lens achromatic and focal length compensation expression between wave band were derived. The system used four lenses and introduces binary diffraction surface by properly matching the optical system power to achieve common optical path. The focal lengths were consistent between the visible and infrared, which improves consistency of dual-band target information. The optical system operating wavelength is 0.38-0.76 ?滋m and 3-5 ?滋m, the focal length of the whole optical system is 90 mm, the field of view is 0.5° and the F number is 3, respectively. The dual-band athermal optical system with the temperature of -40-+60 ℃ was designed with the use of optical passive. The results show that the designed system structure is simple and the size is small, has an excellent in overall image quality..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 5, 518003 (2017)
[in Chinese]
32×32 very long wave infrared HgCdTe FPAs
Hao Lichao, Huang Aibo, Xie Xiaohui, Li Hui, Lai Canxiong, Chen Honglei, Wei Yanfeng, and Ding Ruijun
Very long wave infrared(VLWIR) band is widely used for the remote atmosphere sounding applications, particularly for humidity, CO2 levels, cloud structure and temperature distribution. A 32×32 VLWIR HgCdTe focal plane array(FPA) was designed. The photosensitive component was fabricated by B+ ion implanting As-dopeVery long wave infrared(VLWIR) band is widely used for the remote atmosphere sounding applications, particularly for humidity, CO2 levels, cloud structure and temperature distribution. A 32×32 VLWIR HgCdTe focal plane array(FPA) was designed. The photosensitive component was fabricated by B+ ion implanting As-doped p-type material of liquid phase epitaxial growth on ZnCdTe substrate. The readout integrated circuit(ROIC) used a buffered direct injection(BDI) structure with an improved background suppression. The VLWIR focal plane array(FPA) was achieved by combining the HgCdTe detector with ROIC in terms of indium bump bonds, the cutoff wavelength of which was over 14 ?滋m. The pixel occupied an area of 60 ?滋m×60 ?滋m. It could be operated at the temperatures of 50 K. The test results show that the peak detectivity and blackbody responsivity of PFAs are 2.57×1010 cmHz1/2/W and 1.35×107 V/W, respectively. The nonuniformity of responsivity is about 45%, and dead pixels ratio is less than 12%..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 5, 504001 (2017)
Infrared decoy simulation based on MOS resistance array
Song Minmin, Tang Shanjun, Wang Biyun, Lv Tao, and Fu Xiaohai
In order to verify the performance of infrared guidance missile against infrared decoy, it is necessary to simulate the energy change and motion form of infrared decoy in the actual IR scene in the process of hardware in the loop simulation, that is the variation of the radiation of the infrared decoy and separation ofIn order to verify the performance of infrared guidance missile against infrared decoy, it is necessary to simulate the energy change and motion form of infrared decoy in the actual IR scene in the process of hardware in the loop simulation, that is the variation of the radiation of the infrared decoy and separation of bait with target after the interference was deliveried. For this reason, the infrared decoy simulation was studied by using MOS resistor array. Existing domestic MOS resistor array is not less than 200 Hz refresh frequency, and equivalent blackbody temperature of not less than 300℃ can reproduce well the energy of infrared decoy changing when it is burning, at the same time, the simulation model was established based on the infrared decoy modeling theory, and the infrared decoy motion model was modified based on the collected data in the field, it is mainly infrared decoy trajectory correction. Finally, the simulation of infrared decoy was realized based on MOS dynamic infrared scene rendering and driving software..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 5, 504002 (2017)
Test of infrared search and track system
Wu Xueming, Wang Haiyan, Kou Tian, Kou Renke, and Wang Fang
In view of the problem of simplicity in test project of infrared search and track system(IRST) in current, a test equipment taking into account both operating range and tracking accuracy was designed by combining the theory of operating range test and dynamic target. Temperature-control blackbody and step attenuator moIn view of the problem of simplicity in test project of infrared search and track system(IRST) in current, a test equipment taking into account both operating range and tracking accuracy was designed by combining the theory of operating range test and dynamic target. Temperature-control blackbody and step attenuator module were used to simulate remote target, and arm structure with double mirror has been used to simulate target movement, these could promote simulation effect of dynamic target. The control system of test equipment was designed. On the basis of analyzing test accuracy of each part of equipment, the errors were caused by rotating of arm structure were analyzed emphatically by software of finite element analysis. In the rotating speed of 6 rad/s, the error of tracking accuracy is 0.76″, and equipment could meet requirements of test accuracy. The design provides feasible method and theoretical basis on developing and improving of test equipment of IRST..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 5, 504003 (2017)
A switched-gain proportional navigation applicable for infrared guidance munitions
Zang Luyao, Hou Miao, Wang Hui, Wang Guangshuai, and Lin Defu
Considering the infrared guidance munitions need the information of time-to-go, when using impact angular constraint guidance law, one kind of switched-gain proportional navigation guidance(SGPNG), without time-to-go for it′s input, was proposed. Based on the analytical relationships among the middle-terminal navigatioConsidering the infrared guidance munitions need the information of time-to-go, when using impact angular constraint guidance law, one kind of switched-gain proportional navigation guidance(SGPNG), without time-to-go for it′s input, was proposed. Based on the analytical relationships among the middle-terminal navigation ratio, acceleration constraint and field-of-view constraint when desired terminal impact angle was fixed, the calculation model of navigation gain was established. Then the navigation gain and the location of switched-gain were got. After that, the SGPNG performance was compared with that of trajectory shaping guidance(TSG). Simulation results and the engineering application analysis show that the SGPNG achieves the goal of desired impact angle, location, the field-of-view angle limit and acceleration constraint. Compard with the TSG, the SGPNG needs less hardware resources..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 5, 504004 (2017)
Experiment of target detection based on long-wave infrared hyperspectral polarization technology
Xu Wenbin, Chen Weili, Li Junwei, Wang Guangping, and Wu Jingli
The technique of polarization detection helps improve the ability of detecting and identifying target, which is currently one of the important contents of the research at home and abroad. The measuring principle of infrared hyperspectral polarization was introduced. The measuring system of long wave infrared hyperspectThe technique of polarization detection helps improve the ability of detecting and identifying target, which is currently one of the important contents of the research at home and abroad. The measuring principle of infrared hyperspectral polarization was introduced. The measuring system of long wave infrared hyperspectral polarization was set up. The measuring experiments of polarization characteristic of paint-coating and aluminum-plating target at different temperatures and observing angles were carried out. The effective experimental data was obtained and analysed. The results show that: the spectral polarization characteristic of the target is influenced by temperature and observing angle; the more the difference of temperature and observing angle of the target is, the more the spectral degree of polarization is; the spectral degree of polarization has band selectivity. The effective detection and identification is developed based on the difference of temperature and observing angle of targets. The above results provide reference for band selectivity of the detector..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 5, 504005 (2017)
Diffraction characteristics analysis for DMD-based scene projectors in the long-wave infrared
Han Qing, Wang Jian, Xiong Zheng, Zhang Jianzhong, Ma Junlin, Liu Ying, and Sun Qiang
Diffraction effects play a significant role in DMD-based scene projection in the long-wave infrared band (8-12 μm). The contrast provided by these projector systems can become noticeably worse because of the diffraction effect of the DMD. So it is necessary to analyze the diffraction characteristics of DMD when it is aDiffraction effects play a significant role in DMD-based scene projection in the long-wave infrared band (8-12 μm). The contrast provided by these projector systems can become noticeably worse because of the diffraction effect of the DMD. So it is necessary to analyze the diffraction characteristics of DMD when it is applied to DMD-based scene projector in this wavelength band. Firstly, DMD was treated as a special blazed grating, and a grating diffraction model of DMD was constructed by diffraction theory and Fourier transform. Then, simulation calculation was conducted in MATLAB environment. Finally, the simulation result was verified by experiment of scene projection. It is shown that there exists a suitable illuminating incident angle range to achieve high contrast image in the long-wave infrared(8-12 μm) band. When incident azimuth angle is 0°and incident zenith angle is between 44°and 48°, the scene projector will have a good imaging contrast..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 5, 504006 (2017)
[in Chinese]
Temperature distribution calculation and experiments of Tm:YLF laser
Li Yan, Zhang Yixuan, Na Quanxin, Gao Mingwei, and Gao Chunqing
The structure of double-crystal four-end pumped Tm:YLF laser was designed and studied. By using steady-state thermal analysis module in the Ansys software, the temperature distributions of the two crystal-clamps and cooling plate were calculated with the heat exchange coefficients of the cooling plate channels given asThe structure of double-crystal four-end pumped Tm:YLF laser was designed and studied. By using steady-state thermal analysis module in the Ansys software, the temperature distributions of the two crystal-clamps and cooling plate were calculated with the heat exchange coefficients of the cooling plate channels given as 1 000 W/(m2·℃), 4 000 W/(m2·℃), 8 000 W/(m2·℃) and 15 000 W/(m2·℃). Meanwhile, the temperature distributions when the cooling-plate was assumed as a TEC cooler with temperatures of 18℃ and 20℃ were calculated, respectively. According to the calculated results, the cooling effect when the cooling-plate was given as medium convection intensity or higher would be equal to the result when taking the cooling-plate as TEC with temperature of 18℃ and 20℃. According to the simulation results, a U-shape Tm:YLF laser was designed pumped by fiber coupled laser diode. The output lasers with powers of 25.9 W and 46 W were achieved from single crystal and double crystals when the Tm:YLF crystal clamps and cooling plate were directly cooled by 16℃ cold water, corresponding to slope efficiencies of 40.7% and 37.1%, respectively. No over high temperature was observed in the whole experiment. The experiment results indicate that the designed direct conduction cooling system can effectively remove the heat load in single-crystal dual-end and double-crystal four-end pumped Tm:YLF laser..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 5, 506001 (2017)
Observational study of quasi-monochromatic gravity waves characteristics in mesopause region with sodium fluorescence Doppler lidar
Wang Bo, Hu Xiong, Yan Zhaoai, Xiao Cunying, Guo Shangyong, Cheng Yongqiang, and Guo Wenjie
The quasi-monochromatic gravity waves（QM GWs)parameters in the mesopause region over Langfang (39.4°N, 116.6°E) were studied based on the 60 h sodium fluorescence Doppler lidar data during 2011-2013 year. A total of 85 QM GWs were extracted from the simultaneously measured temperature and wind profiles betweeThe quasi-monochromatic gravity waves（QM GWs)parameters in the mesopause region over Langfang (39.4°N, 116.6°E) were studied based on the 60 h sodium fluorescence Doppler lidar data during 2011-2013 year. A total of 85 QM GWs were extracted from the simultaneously measured temperature and wind profiles between 85 km and 95 km using hodograph method. The result shows that vertical wavelengths (horizontal wavelengths) and observed periods are mainly distributed from 6 km to 9 km(200 km to 800 km) and 2 h to 7 h, with the mean values 6.6 km (727.8 km) and 7.4 h respectively. GWs propagating upward in the vertical direction are with an occurrence of 75.29%. The intrinsic periods are mainly distributed from 3 h to 9 h with a mean value 7.76 h. There is no dominant horizontal propagation direction. The probability of the horizontal background wind component along the horizontal propagate direction Up>0 is about 50% for upward GWs, but for downward GWs the probability of Up>0 is about 66.66%, which is about 2 times of the probability of Up<0(33.33%), which suggests that the observed downward GWs are mainly propagating horizontally along the wind..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 5, 506002 (2017)
Phase modulated lidar imaging design and simulation
Huang Yuxiang, Zhang Hongyi1, Li Fei1, Xu Weiming1, and Hu Yihua
The inverse synthetic aperture lidar(ISAL) have attracted increasing attention for its merits including smaller divergence angle of the signal source and smaller synthetic aperture under same cross-range resolution when compared with its inverse synthetic aperture radar (ISAR) counterpart. However, by using lidar insteThe inverse synthetic aperture lidar(ISAL) have attracted increasing attention for its merits including smaller divergence angle of the signal source and smaller synthetic aperture under same cross-range resolution when compared with its inverse synthetic aperture radar (ISAR) counterpart. However, by using lidar instead of radar as the signal source, the most popular spread-spectrum techniques such as linear frequency modulation are not suitable for a practical ISAL. In order to obtain a highly repeatable and a broad frequency signal in a very short time, a maximum length sequence coded phase modulation method, which was a widespread method in optical communication, was adopted in this paper. The far-field signal model and the corresponding imaging algorithm were introduced in the first place. The main differences from traditional algorithms were addressed thereafter. Finally, a well-designed simulation target composed of several scattered center points was used to verify the validity of the proposed imaging algorithm. The results are analyzed with imaging parameters to prove the method introduced by this paper is adaptable for real-time ISAL..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 5, 506003 (2017)
Microstructure and micro-hardness of laser deposition repair ZL114A aluminum alloy
Qin Lanyun, Pang Shuang, Yang Guang, Wang Chao, and Wang Wei
To study the process and properties of laser deposition repair(LDR) ZL114A aluminum alloy samples, the basic process experiment of multi parameter combination was accomplished by laser single-pass process, on the basis of analyzing surface features, the reasons of gas porosity, a set of optimized process parameters werTo study the process and properties of laser deposition repair(LDR) ZL114A aluminum alloy samples, the basic process experiment of multi parameter combination was accomplished by laser single-pass process, on the basis of analyzing surface features, the reasons of gas porosity, a set of optimized process parameters were obtained, and defect-free block specimens were prepared, microstructure analysis and hardness testing of the samples were carried out. Results show that the repair area and the substrate form a good metallurgical combination. α-Al columnar dendrites took melt pool edge as a starting point at the bottom of the deposition layer. The primary dendrites arm spacing was 18.38 μm and the distance between dendrite crystal was 9.55 μm. On the top of the deposited layers, α-Al dendrite columnar crystal was changed into equiaxed dendrite microstructure. Si phase was precipitated and tended to be spheroidize in the layer band of the repaired zone. Due to the function of grain refinement and solution strengthening, the micro-hardness of the deposited area was 25.8% higher than that of the substrate..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 5, 506004 (2017)
Trajectory planning of laser cladding remanufacturing for complex shaft shaped part
Huang Yong, Sun Wenlei, and Chen Ying
It is difficult to achieve trajectory planning and automatic programming for the remanufacturing of complex shaft shaped part. Aiming at this case, reverse measurement was completed based on non uniform rational B-spline(NURBS) curve for surface of part. A constant arc increment interpolation method was presented for lIt is difficult to achieve trajectory planning and automatic programming for the remanufacturing of complex shaft shaped part. Aiming at this case, reverse measurement was completed based on non uniform rational B-spline(NURBS) curve for surface of part. A constant arc increment interpolation method was presented for laser cladding remanufacturing and the Newton iteration algorithm based on Romberg integral method was proposed and designed. A program based on 6 DOF robot was developed for trajectory planning and computer aided programming. The morphology, microstructure, thickness and micro-hardness of layer were tested and analyzed. It is observed that, the cladding layer and substrate have a good metallurgical bond, layer thickness is uniform, when the max laser beam tilt angle from the horizontal is 42°, cladding thickness decreases 0.034 mm compared with maximum thickness, the micro-hardness is significantly higher than the substrate. Experimental results show the effectiveness of the method proposed..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 5, 506005 (2017)
CO gas system of quasi-continuous laser modulation absorption spectroscopy
Shao Xin, Wang Feng, Zhang Xinghui, Chen Wenliang, and Yang Bin
Quasi-continuous signal is an important form of modulation signal, which is widely used in many fields. Quasi-continuous modulation laser absorption spectroscopy was one of the typical applications of quasi-continuous signal, includes advantageous features of speediness, sensitivity and accuracy. In the environment of Quasi-continuous signal is an important form of modulation signal, which is widely used in many fields. Quasi-continuous modulation laser absorption spectroscopy was one of the typical applications of quasi-continuous signal, includes advantageous features of speediness, sensitivity and accuracy. In the environment of earthquakes, landslides, fires and other disasters, it was possible to produce CO, which was a kind of extremely flammable, explosive, toxic and harmful gas, due to the accumulation of complex closed environment and incomplete combustion. Therefore, to avoid the second explosion injury, rescue robot need to monitor and analyze the gas environment in the disaster scene. CO was the research object in this system. An experimental system for quasi-continuous modulation laser absorption spectroscopy measurement was established. The system has carried out CO measurement experiments by changing concentration, pressure and temperature, achieved the formulas for the relationship between second harmonic signal and CO concentration, pressure and temperature in actual CO measurements respectively. These formulas can be used to automatically compensate CO concentration according to the real-time pressure and temperature value during the rescue robot′s measurement in the disaster scene.(2012YQ06016501); 天津中德应用技术大学科技培育重点项目(zdkt2016-001).
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 5, 506006 (2017)
[in Chinese]
Trajectory outlier detection based on DBSCAN clustering algorithm
Zhou Peipei, Ding Qinghai, Luo Haibo, and Hou Xinglin
Existing traditional trajectory outlier detection algorithms always focus on spatial outliers and ignore temporal outliers, and the accuracy is relatively low. To solve these problems, a simple and effective approach based on enhanced clustering algorithm was proposed to detect spatio-temporal trajectory outliers. FirsExisting traditional trajectory outlier detection algorithms always focus on spatial outliers and ignore temporal outliers, and the accuracy is relatively low. To solve these problems, a simple and effective approach based on enhanced clustering algorithm was proposed to detect spatio-temporal trajectory outliers. Firstly, each original trajectory was simplified into a set of sequential line segments with the velocity-based minimum description length(VMDL) partition principle. Secondly, the distance formula between line segments was improved to enhance the clustering performance. Using DBSCAN algorithm, the line segments were classified into different groups which could represent local normal behaviors. Thirdly, outliers were detected using two-level detection algorithm which first detected spatial outliers and then detected temporal outliers. Experimental results on multiple trajectory data sets demonstrate that the proposed algorithm could successfully detect three kinds of spatio-temporal outliers, position, angle and velocity. Compared with other methods, the precision and accuracy make great improvement..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 5, 528001 (2017)
[in Chinese]
Extinction characteristic of terahertz wave by carbon smoke materials
Wang Qichao, Wang Jiachun, Zhao Dapeng, Chen Zongsheng, Dong Hailong, and Shi Jiaming
In order to acquire extinction characteristics of smokes for terahertz (THz) wave, graphite and carbon black powders were mixed respectively into KBr powder with some certain proportions, and the admixtures were pressed into tablets to measure the THz transmission spectrums using THz time-domain spectroscopy (THz-TDS) In order to acquire extinction characteristics of smokes for terahertz (THz) wave, graphite and carbon black powders were mixed respectively into KBr powder with some certain proportions, and the admixtures were pressed into tablets to measure the THz transmission spectrums using THz time-domain spectroscopy (THz-TDS) from 0.2 to 1.1 THz. At the same time, the THz signal was acquired from the pure KBr powder tablet, which was prepared with same method under same condition. Then, absorption coefficients of graphite and carbon black tablets were deduced based on material parameter estimation method. The result indicates that absorption coefficients of those tablets are enhanced with the increasing frequency and they are improved with the proportions of smoke powders at the same frequency. The absorption coefficient of tablet filled with carbon black powder is greater than it of graphite tablet. The final results demonstrate that THz wave has stronger penetration capacity through graphite smoke, and carbon black is a promising jamming material for THz detection..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 5, 525001 (2017)
Caussian beam shaping terahertz Gaussian beam to ring beam
Ma Xue, Li Qi, and Lu Jianye
In many practical applications, it is required that the spot is ring distributed. Therefore, it is important to do the experimental research of converting the terahertz Gaussian beam to a ring beam. In the paper, a phase plate was designed using GS algorithm, converting the Gaussian beam with frequency of terahertz banIn many practical applications, it is required that the spot is ring distributed. Therefore, it is important to do the experimental research of converting the terahertz Gaussian beam to a ring beam. In the paper, a phase plate was designed using GS algorithm, converting the Gaussian beam with frequency of terahertz band to a ring beam. The shaping effect of multi-order encoding phase plates was discussed. According to different transmission distances, different simulations were done. Using the PyrocamⅢ as the recording device, beam shaping experiments were carried out on different distance. The experimental results show that the experimental results are close to the simulation results..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 5, 525002 (2017)
Accurate and rapid extraction of optical parameters for thin plates with terahertz time-domain spectroscopy technology
Han Xiaohui, Cui Hongliang, Zhang Jin, Yang Ye, Ma Yuting, Dai Guangbin, Li Mingliang, and Chang Tianying
Due to the low THz radiation energy and narrow pulse width(picosecond range), as a new spectral analysis method, terahertz time-domain spectroscopy(THz-TDS) technology is nondestructive and high-temporal-resolution when being used to extract optical parameters of samples. Fabry-Pérot interference is a crucial obstDue to the low THz radiation energy and narrow pulse width(picosecond range), as a new spectral analysis method, terahertz time-domain spectroscopy(THz-TDS) technology is nondestructive and high-temporal-resolution when being used to extract optical parameters of samples. Fabry-Pérot interference is a crucial obstacle in extracting optical parameters of thin wafers in the THz-TDS through-transmission mode. A reliable algorithm was proposed and tested to simultaneously filter Fabry-Pérot interference and obtain precise optical characterization of thin wafers. The algorithm employs a band-stop filter immediately and exclusively designed for every single sample to the initial refractive index and absorption coefficient. Experimental results of doped silicon wafers and amino acid tablets confirming the utility of the algorithm were also presented..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 5, 525003 (2017)
[in Chinese]
Damage growth characteristics of artificial nodules prepared by different processes
Ma Hongping, Cheng Xinbin, Zhang Jinlong, Wang Zhanshan, and Tang Yongjian
Damage growth behaviors play an equal important role in limiting the laser resistance of high reflectors (HR) on high power laser systems as initial damage. In order to build damage mechanism and improve the laser resistance of coatings, it is necessary to obtain more information about damage growth behaviors. Thus a cDamage growth behaviors play an equal important role in limiting the laser resistance of high reflectors (HR) on high power laser systems as initial damage. In order to build damage mechanism and improve the laser resistance of coatings, it is necessary to obtain more information about damage growth behaviors. Thus a comparative experiment was designed to study the damage growth characteristics of different size of nodular defects in HfO2/SiO2 high reflectors working at 1 064 nm. Two kinds of HfO2/SiO2 high reflectors were prepared by EB and IAD process, respectively, and four sizes of SiO2 microspheres were used to create artificial nodules in these films. Then the relationship between damage growth characteristics with nodule size and film deposition processes was studied. Laser damage test results showed that the damage growth threshold decreased with the increase of nodule size for all sizes of nodules in both EB and IAD coatings. The damage growth threshold were higher than the initial damage threshold for all four sizes of nodules in coatings prepared by EB process, however, the results were opposite for all four sizes of nodules in coatings prepared by IAD process. Besides, IAD nodules were more easily to grow than EB nodules, which indicated that the film deposition processes has some influence on the damage growth speed of nodules..
Infrared and Laser Engineering
- Publication Date: Jan. 01, 1900
- Vol. 46, Issue 5, 521001 (2017)
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