Journals >Journal of Infrared and Millimeter Waves
Contents
2009
Volume: 28 Issue 4
18 Article(s)
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Research Article
NEW METHOD FOR PAPER BASIS WEIGHT MEASUREMENT BASED ON TERAHERTZ TIME DOMAIN SPECTROSCOPY
CAO Bing-Hua, ZHANG Guang-Xin, and ZHOU Ze-Kui
Measurement of basis weight which is one of the most important physical indexes of paper sheet is of decisive importance in paper making process. However, this problem has not been well solved so far. Terahertz time domain spectroscopy is a newly developed spectroscopy technique based on femtosecond laser technology, aMeasurement of basis weight which is one of the most important physical indexes of paper sheet is of decisive importance in paper making process. However, this problem has not been well solved so far. Terahertz time domain spectroscopy is a newly developed spectroscopy technique based on femtosecond laser technology, and has been studied in some other research fields. The purpose of this work is to study the feasibility of applying terahertz time-domain spectroscopy technique to the measurement of paper sheet basis weight. Two principles were presented in this study. One was based on terahertz amplitude attenuation and the other was on terahertz delay time. Experiments were carried out to verify the theoretical analysis and compare the performances of these two proposed principles. The experimental results show that delay-time-based method is better than amplitude-attenuation-based method in terms of linearity and accuracy. The research work indicates that the method based on terahertz delay time is feasible for paper basis weight measurement. And it may provide a new solution for paper basis weight measurement.
Journal of Infrared and Millimeter Waves
- Publication Date: Oct. 31, 2021
- Vol. 28, Issue 4, 241 (2009)
CONTROL OF SURFACE DEFECTS IN HgCdTe FILM GROWN BY LIQUID PHASE EPITAXY
WEI Yan-Feng, XU Qing-Qing, CHEN Xiao-Jing, ZHANG Chuan-Jie, SUN Shi-Wen, FANG Wei-Zheng, and YANG Jian-Rong
Liquid phase epitaxy is a developed technique for the growth of HgCdTe films. Two kinds of macro defects on the surface of HgCdTe film were studied. It was demonstrated that the origin of the void defects was related to the wax contamination on CdZnTe substrate, while the defects of hill-like were due to the CdZnTe parLiquid phase epitaxy is a developed technique for the growth of HgCdTe films. Two kinds of macro defects on the surface of HgCdTe film were studied. It was demonstrated that the origin of the void defects was related to the wax contamination on CdZnTe substrate, while the defects of hill-like were due to the CdZnTe particles detached from the edge of the CdZnTe substrate. Through the fine controlling during the substrate preparation, these two kinds of defects can be depressed and the high quality HgCdTe films with zero defect density can be obtained..
Journal of Infrared and Millimeter Waves
- Publication Date: Oct. 31, 2021
- Vol. 28, Issue 4, 246 (2009)
EFFECT OF REFLECTOR DEFORMATION ON OPTICAL DETECTION SENSITIVITY FOR OPTICAL READOUT INFRARED IMAGING SYSTEM
GAO Jie, ZHANG Qing-Chuan, CHEN Da-Peng, JIAO Bin-Bin, SHI Hai-Tao, QIAN Jian, CHENG Teng, and WU Xiao-Ping
Based on the optical readout method with knife edge filter, the relationship between the optical detection sensitivity and reflector length was discussed under the circumstance that the reflector was bent. Analysis indicates that the optical sensitivity increases with the reflector's lengthening at first, then it rBased on the optical readout method with knife edge filter, the relationship between the optical detection sensitivity and reflector length was discussed under the circumstance that the reflector was bent. Analysis indicates that the optical sensitivity increases with the reflector's lengthening at first, then it reaches a maximum value, and then it decreases as the reflector continues to lengthen. For the reflectors with different curvature radii and lengths, analysis shows that the sensitivity will reach a maximum value when the expression L 2 /R=λ ( L is length of reflector, R is curvature of the reflector, λ is wavelength of illumination light) is satisfied. The optical detection sensitivities of the fabricated FPAs with different pixel sizes as 200μm, 120μm and 60μm were obtained experimentally. The result coincides with the theoretical analysis..
Journal of Infrared and Millimeter Waves
- Publication Date: Oct. 31, 2021
- Vol. 28, Issue 4, 249 (2009)
FUSION OF INFRARED AND VISIBLE IMAGES BASED ON THE SECOND GENERATION CURVELET TRANSFORM
FU Meng-Yin, and ZHAO Cheng
Aiming at the physical characteristics of infrared and visible imaging sensors, a novel image fusion algorithm based on the second generation Curvelet transform was proposed. Firstly, the fast discrete Curvelet transform was performed on the original images respectively to obtain the subband coefficients at different sAiming at the physical characteristics of infrared and visible imaging sensors, a novel image fusion algorithm based on the second generation Curvelet transform was proposed. Firstly, the fast discrete Curvelet transform was performed on the original images respectively to obtain the subband coefficients at different scales and in various directions. Then for low frequency subband coefficients, the fusion weights were determined by the target characteristics of infrared image and the detail information of visible image; while for high frequency subband coefficients, a fusion rule based on local-region energy matching was employed. Finally, the fusion results were obtained through the inverse Curvelet transform. Experimental results show that the proposed algorithm can effectively integrate important information from infrared and visible images, and the obtained results are better than those of pyramid-based or wavelet-based algorithms..
Journal of Infrared and Millimeter Waves
- Publication Date: Oct. 31, 2021
- Vol. 28, Issue 4, 254 (2009)
SYNTHESIS AND CHARACTERIZATION OF Bi2Cu0.1V0.9O5.35-δ SOLID ELECTROLYTE VIA CHEMICAL SOLUTION PROCESS
GUO Ming, MENG Xiang-Jian, YANG Ping-Xiong, and CHU Jun-Hao
Bi 2 Cu 0.1 V 0.9 O 5.35-δ (BICUVOX.10) materials were prepared by chemical solution process, and the phases, surface morphology and electrical properties of the materials were studied. Our results show that the higher-conducting γ-phase of the BICUVOX.10 thin films is stabilized at room temperature. The BICUVOX.10 thiBi 2 Cu 0.1 V 0.9 O 5.35-δ (BICUVOX.10) materials were prepared by chemical solution process, and the phases, surface morphology and electrical properties of the materials were studied. Our results show that the higher-conducting γ-phase of the BICUVOX.10 thin films is stabilized at room temperature. The BICUVOX.10 thin films deposited on LaNiO 3 /Si substrates are preferred (001) orientation and the mean grain size of the films is about 200 nm. The dielectric dispersion of the films may be originated from the short distance diffusion of oxygen vacancies in the low frequency region. The grain boundary dominates the conduction for the BICUVOX.10 thin films. The activation energy of oxygen ionic conduction in the BICUVOX.10 thin films is about 0.3 eV. The oxygen ionic conductivity is about 5×10-2 S·cm -1 ..
Journal of Infrared and Millimeter Waves
- Publication Date: Oct. 31, 2021
- Vol. 28, Issue 4, 259 (2009)
STUDY ON THE SCINTILLATING PROPERTIES OF IONS DOPED LEAD TUNGSTATE SCINTILLATION CRYSTALS
WAN You-Bao, WU Yu-Rong, ZHANG Jian-Xin, YANG Pei-Zhi, XIAO Lin-Rong, and YANG Hui
PbWO 4 and BaF 2 :PbWO 4 were grown by multi-crucible temperature gradient system. The transmittance spectra and x-ray excited luminescence spectra of as-grown PbWO 4 , annealed PbWO 4 and annealed BaF 2 :PbWO 4 were studied. The results reveal that these properties are related to the composition and growth arts of thePbWO 4 and BaF 2 :PbWO 4 were grown by multi-crucible temperature gradient system. The transmittance spectra and x-ray excited luminescence spectra of as-grown PbWO 4 , annealed PbWO 4 and annealed BaF 2 :PbWO 4 were studied. The results reveal that these properties are related to the composition and growth arts of the crystals. The facts are complicated for the crystals annealing. In the wavelength range above 360nm, the transmittance for the annealed crystal is better than that of the as-grown crystal, while it is a little weaker than that of the as-grown crystal in the wavelength range of 320 ～360nm. For the x-ray excited luminescence spectra, the spectrum intensity of the annealed crystal is higher than that of as-grown crystal in the wavelength range above 380nm, while it is a little weaker than that of as-grown crystal in the wavelength range of 320～380nm. The doping ions improve the transmittance and the x-ray excited luminescence spectrum intensity. These phenomena are explained based on the relations of the defect, crystal growth arts and the optical properties of these crystals. For the BaF 2 :PbWO 4 crystal, it's peak shape and intensity of x-ray excited luminescence spectrum are evidently changed than PbWO4 crystal. The phenomenon may relate to the fact that ［WO 4 ］ 2tetrahedron of the crystal is degenerated when it is doped with F ions, and the degeneration will induce a new luminescent center..
Journal of Infrared and Millimeter Waves
- Publication Date: Oct. 31, 2021
- Vol. 28, Issue 4, 263 (2009)
DETECTION OF SPAD VALUE OF CUCUMBER LEAVES BASED ON VISIBLE/NEAR INFRARED SPECTROSCOPY TECHNIQUE
LIU Fei, WANG Li, HE Yong, and BAO Yi-Dan
For the rapid detection of SPAD value of cucumber leaves, the calibration model of SPAD value was built by using visible and near infrared (Vis/NIR) spectroscopy technique and chemometrics methods. Different calibration methods were used to build the model in the whole wavelength region. The results indicate that the oFor the rapid detection of SPAD value of cucumber leaves, the calibration model of SPAD value was built by using visible and near infrared (Vis/NIR) spectroscopy technique and chemometrics methods. Different calibration methods were used to build the model in the whole wavelength region. The results indicate that the optimal performance is achieved by least squares support vector machine(LSSVM) model, and the correlation coefficient ( r ) and root mean squares error of prediction (RMSEP) are 0.9583 and 0.9732, respectively. Via the analysis of correlation coefficients between the spectral reflectance and SPAD values, and the regression coefficients of partial least squares (PLS), two characteristic wavelength bands (531～581nm and 696～716nm) and four characteristic wavelengths (556, 581, 698 and 715nm) were obtained. LSSVM was used to the aforementioned wavelength bands and wavelengths. The results indicate that the characteristic wavelength bands can achieve a better performance with r of 0.9338 and RMSEP of 1.1370. The prediction results are similar to the whole wavelength region model, while, the performance of LSSVM model with four characteristic wavelengths was not satisfying. Calibration method of using characteristic wavelength bands can largely reduce the calibration computation, and increase the calibration speed. Hence, it is more effective to use characteristic wavelength bands for the detection of SPAD values of cucumber leaves..
Journal of Infrared and Millimeter Waves
- Publication Date: Oct. 31, 2021
- Vol. 28, Issue 4, 272 (2009)
DETERMINATION OF NITROGEN IN RICE LEAF BASED ON FTIR SPECTRA AND siPLS-GA-PLS ALGORITHM
LIN Fen-Fang, CHEN Zhu-Lu, WANG Ke, DENG Jin-Song, and XU Hong-Wei
The Fourier transform mid-infrared (FT-MIR) spectra and nitrogen concentration were measured from dried leaves of rice in booting stage under various treatments of nitrogen fertilization. The synergy interval partial least square algorithm (si-PLS) combined with genetic algorithm (GA) was applied to the selection of opThe Fourier transform mid-infrared (FT-MIR) spectra and nitrogen concentration were measured from dried leaves of rice in booting stage under various treatments of nitrogen fertilization. The synergy interval partial least square algorithm (si-PLS) combined with genetic algorithm (GA) was applied to the selection of optimal variables. 84 variables were determined to build the estimation model for leaf nitrogen content. The prediction accuracy of the PLS regression model based on these variables was better than that of the siPLS model or the model from spectral index NFSA. The RMSEP (root mean square error of prediction) is 0.1186 and r (correlation coefficient) is 0.9120. The results show that FTIR spectra combined with siPLS-GA-PLS algorithm can be used successfully to analyze leaf nitrogen concentration of rice..
Journal of Infrared and Millimeter Waves
- Publication Date: Oct. 31, 2021
- Vol. 28, Issue 4, 277 (2009)
COLOR CONTRAST ENHANCEMENT METHOD TO IMPROVE TARGET DETECTABILITY IN NIGHT VISION FUSION
YIN Song-Feng, CAO Liang-Cai, YANG Hua, TAN Qiao-Feng, HE Qing-Sheng, LING Yong-Shun, and JIN Guo-Fan
Requirements on color image fusion for situation awareness and target detection tasks were analyzed based on the characteristics of human visual system. Then a night vision fusion method was presented to improve target detectability by enhancing color contrast between the target and the background. The proposed fusion Requirements on color image fusion for situation awareness and target detection tasks were analyzed based on the characteristics of human visual system. Then a night vision fusion method was presented to improve target detectability by enhancing color contrast between the target and the background. The proposed fusion method relates hot and cold targets to the colors of intense red and cyan, respectively. According to the characteristics of infrared images, a color contrast enhancement ratio related to the divergence of the intensity of each pixel from the mean intensity of the infrared image was utilized to enhance color contrast between the target and the background. The enhancing method offsets the disadvantage of color transfer method in color contrast and improves target detectability. Experimental results demonstrate that the method can not only pop out both hot and cold targets, but also keep details of the background well. The situation awareness and target detectability can be improved by the method..
Journal of Infrared and Millimeter Waves
- Publication Date: Oct. 31, 2021
- Vol. 28, Issue 4, 281 (2009)
RESEARCH ON LASER ALTIMETER'S FIELD OF VIEW
DI Hui-Ge, WANG Jian-Yu, FANG Kang-Mei, and SHU Rong
Laser altimeter's field of view (FOV) is an important parameter affecting system's performance. The effect of the field of view on the detection performance of system was discussed. Because of the straylight and the sensor's nonuniformity, the FOV changes as the echo's power changes. At the same time thLaser altimeter's field of view (FOV) is an important parameter affecting system's performance. The effect of the field of view on the detection performance of system was discussed. Because of the straylight and the sensor's nonuniformity, the FOV changes as the echo's power changes. At the same time the echo's power will be varied with the detecting distance. The testing way of detecting FOV was put forward, and the factual working status was simulated. For system with inner short-range delay protecting circuit, a new method was brought forward. A laser altimeter with the FOV of 1.5mrad was tested. The FOV of the system is 1.46mrad when its detecting distance is 200km and the echo's power is 5×10 -8 W..
Journal of Infrared and Millimeter Waves
- Publication Date: Oct. 31, 2021
- Vol. 28, Issue 4, 285 (2009)
THERMAL EMISSION CHARACTERISTICS OF A NEGATIVE INDEX SEMITRANSPARENT THIN FILM
HUANG Yong, CUI Yi, and WANG Jun
Thermal emission characteristics of a negative index semitransparent thin film were studied based on transmit matrix method and Kirchhoff radiation law. The influence of different parameters on the emissivity of s-polarization wave was studied. The results show that a complicated oscillation will happen when the angulaThermal emission characteristics of a negative index semitransparent thin film were studied based on transmit matrix method and Kirchhoff radiation law. The influence of different parameters on the emissivity of s-polarization wave was studied. The results show that a complicated oscillation will happen when the angular frequency increases. It also shows that the peak value of the emissivity is sometimes far away from the normal direction..
Journal of Infrared and Millimeter Waves
- Publication Date: Oct. 31, 2021
- Vol. 28, Issue 4, 289 (2009)
AUTOMATIC IDENTIFICATION OF SALIENT OBJECT BASED ON MULTI-FEATURES IMAGES
PIAN Zhao-Yu, MENG Xiang-Ping, and SHU Ying-Li
Many existing detecting algorithms of salient object mostly depend on the relationship between the pixels and lack the comprehension of salient object features. An unsupervised algorithm for automatically extracting the interesting object was presented. Firstly, the junior feature was extracted as basic elements of salMany existing detecting algorithms of salient object mostly depend on the relationship between the pixels and lack the comprehension of salient object features. An unsupervised algorithm for automatically extracting the interesting object was presented. Firstly, the junior feature was extracted as basic elements of salient object by using a multiscale Gabor model with bionics characteristics. Then by combining with the understanding knowledge of the salient object, the local feature of image was defined and the salient regions was further located. Finally, a novel extracting scheme based on fuzzy threshold approach was proposed, and was used in the conspicuity map integrated by the junior and local features to locate the salient object. By applying the algorithm to various images of simulation experiments, the satisfying results were obtained. The results show that the algorithm is feasible..
Journal of Infrared and Millimeter Waves
- Publication Date: Oct. 31, 2021
- Vol. 28, Issue 4, 293 (2009)
NEW METHOD OF MULTIPLE DESCRIPTION CODING FOR IMAGE BASED ON COMPRESSED SENSING
LIU Dan-Hua, SHI Guang-Ming, ZHOU Jia-She, GAO Da-Hua, and WU Jia-Ji
Based on compressed sensing (CS), a new multiple description coding method (CS-MDC) was presented. The new method is robust to packet loss or bit error, and has the advantages of simple structure and easy implementation. The method partitioned an image into several blocks by interleaving extracting in the wavelet domaiBased on compressed sensing (CS), a new multiple description coding method (CS-MDC) was presented. The new method is robust to packet loss or bit error, and has the advantages of simple structure and easy implementation. The method partitioned an image into several blocks by interleaving extracting in the wavelet domain, and made random measurements of the image blocks, and then formed multiple descriptions after quantizing and packing. At the decoding end, it reconstructed the original image approximately or exactly with the received bit streams by solving an optimization problem. The proposed method can construct more descriptions with lower complexity because the process of random measuring is simple and easy to realize. Experimental results show that the proposed method exhibits its superiority over SPIHT-MDC with the same packet loss probability, and it can easily generate more descriptions..
Journal of Infrared and Millimeter Waves
- Publication Date: Oct. 31, 2021
- Vol. 28, Issue 4, 298 (2009)
PHASE MEASURED AND CONTROLLED TECHNOLOGY BASED ON ITS BASIC AND HARMONIC LASER BEAM IN COHERENT CONTROL
LEI Liang, CHEN Li, XU Chu-Dong, LAI Tian-Shu, and LIN Wei-Zhu
In ultrafast optical coherent control, the existence of the phase distortion and phase inconsistence on fundamental frequency and its second harmonic generation laser wavefront leads to fail to achieve the desired experiment results in most cases. An experimental method in diagnosing such distortion situation was desigIn ultrafast optical coherent control, the existence of the phase distortion and phase inconsistence on fundamental frequency and its second harmonic generation laser wavefront leads to fail to achieve the desired experiment results in most cases. An experimental method in diagnosing such distortion situation was designed to make an effective auto-control system applied sucessfully in the coherent control photocurrent experiments. The retrieval algorithm was used, and the spatial surface structure was calculated based on the relationship between the beam intensity and phase difference, thus the voltage or direction was achieved. In this way, the mobile-mirror moves to less aberration. The mentioned experimental result proves that the system can adjust the two wavefronts being parallel automatically in real time..
Journal of Infrared and Millimeter Waves
- Publication Date: Oct. 31, 2021
- Vol. 28, Issue 4, 303 (2009)
DESIGN AND FABRICATION OF VISIBLE+1.54μm LASER/ LONGWAVE INFRARED DICHROIC BEAMSPLITTER
ZHANG Yue-Guang, WANG Ying, SUN Xue-Zheng, SHEN Wei-Dong, LIU Xu, and GU Pei-Fu
Visible+1.54μm laser/longwave infrared dichroic beamsplitters, which separate the incident spectrum into visible light, laser and longwave infrared light, take an important role in multichannel imaging spectrum technique. The choice of substrates and coating materials was discussed. Then the coating design of reflectinVisible+1.54μm laser/longwave infrared dichroic beamsplitters, which separate the incident spectrum into visible light, laser and longwave infrared light, take an important role in multichannel imaging spectrum technique. The choice of substrates and coating materials was discussed. Then the coating design of reflecting the visible(400～800nm) and laser (1540nm) light while transmitting the longwave infrared(8～12μm) spectrum was analysed, and the beamsplitter was manufactured by e-gun evaporation.The measured reflectivity and transmittance of the corresponding channel are all above 94% and the dichroic beamsplitters has been used in practical optical system successfully..
Journal of Infrared and Millimeter Waves
- Publication Date: Oct. 31, 2021
- Vol. 28, Issue 4, 307 (2009)
SAR IMAGE COMPRESSION BASED ON LIFTING DIRECTIONLET TRANSFORM
BAI Jing, WU Jia-Ji, WANG Lei, and JIAO Li-Cheng
A novel SAR image compression algorithm was presented by using lifting directionlet transform(LDT). The lifting directionlet scheme and improved quad-tree segmentation were proposed to obtain the optimal pair of transform directions, which could capture the image features efficiently. To enhance the coder performance, A novel SAR image compression algorithm was presented by using lifting directionlet transform(LDT). The lifting directionlet scheme and improved quad-tree segmentation were proposed to obtain the optimal pair of transform directions, which could capture the image features efficiently. To enhance the coder performance, multi-directional anisotropy hierarchical zerotree was designed, which was suitable to the distribution characteristic of LDT coefficients. Experimental results of real SAR images show that the proposed compression algorithm outperforms the wavelet-based SPIHT and JPEG2000 both in terms of evaluation metric as well as visual quality, especially at the low-bitrate..
Journal of Infrared and Millimeter Waves
- Publication Date: Oct. 31, 2021
- Vol. 28, Issue 4, 311 (2009)
FIELD COLLECTED PLANT SPECTRUM DENOISING BY LOGARITHM TRANSFORM AND WAVELET TRANSFORM
ZHOU Guang-Zhu, WANG Cui-Zhen, YANG Feng-Jie, and LI Yin-Ming
The objects' spectrum is often contaminated by noise when it is collected in the open air. According to the principle of the spectrum collection, the noise was considered as one kind of multiplicative compound noise. By theoretical derivation, the combination of logarithm transform and wavelet transform was introduThe objects' spectrum is often contaminated by noise when it is collected in the open air. According to the principle of the spectrum collection, the noise was considered as one kind of multiplicative compound noise. By theoretical derivation, the combination of logarithm transform and wavelet transform was introduced into noise reduction. Multiplicative noise simulation test was carried out. And the results show that the spatial correlation algorithm is best suited for spectral data denoising, modulus maxima algorithm is inferior to it. Threshold shrinking rule is unsuitable for spectrum denoising. The wild plants spectrum were processed based on spatial correlation algorithm. Results show that the noise near 1450 nm in the spectrum is perfectly denoised, while near 1800 ～ 1900 nm strong noise can not be removed perfectly. The reason is the limited records accuracy of the spectrometer. When the theoretical ratio is far greater than 1, the spectrometer will accurately record them. While the theoretical ratio is far less than 1, the record will be 0. So serious system errors will be generated in strong noise band and will be retained after the wavelet transform was applied because they are considered as signal singularity. Experiments prove that spatial correlative filtering with the combination of logarithm transform and wavelet transform is feasible for multiplicative-noise-contaminated spectrum denoising.
Journal of Infrared and Millimeter Waves
- Publication Date: Oct. 31, 2021
- Vol. 28, Issue 4, 316 (2009)
Image Processing and Software Simulation
MULTI-ANGULAR POLARIZED RADIATION CHARACTERISTICS OF WATER CLOUDS
CHENG Tian-Hai, GU Xing-Fa, YU Tao, CHEN Liang-Fu, and TIAN Guo-Liang
Water clouds, which are distributed at the bottom of atmosphere and composed of spherical water droplets, play an important role in Earth's radiation balance and global climate change. The effects of water clouds are based on their microphysical and optical properties. Based on the studies of water clouds optical pWater clouds, which are distributed at the bottom of atmosphere and composed of spherical water droplets, play an important role in Earth's radiation balance and global climate change. The effects of water clouds are based on their microphysical and optical properties. Based on the studies of water clouds optical properties in 0.865μm, the sensitivity of normalized radiance and polarized radiance intensities to water clouds optical parameters, such as effective radius, optical thickness and surface albedo, was evaluated by using vector radiative transfer model. The simulated results indicate that the information of multidirectional polarized radiance can show the microphysical and optical properties of water clouds effectively, which can be used to retrieve the properties of water clouds. This study provides the basis for using the remote sensing data of multi-angular polarization to retrieve the properties of water clouds was proposed..
Journal of Infrared and Millimeter Waves
- Publication Date: Oct. 31, 2021
- Vol. 28, Issue 4, 267 (2009)
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