Journals >Infrared and Laser Engineering
Contents
2002
Volume: 31 Issue 4
21 Article(s)
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Research Article
IR sub-system of radar/IR dual mode seeker
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The characteristic of IR sub-system of radar/IR dual mode seeker is described. The scheme of applying the single-channel controlled non-imaging IR system to the radar/IR dual mode seeker is discussed. The possible improving approaches, such as space scanning, coordinate conversion, are introduced, and these approaches The characteristic of IR sub-system of radar/IR dual mode seeker is described. The scheme of applying the single-channel controlled non-imaging IR system to the radar/IR dual mode seeker is discussed. The possible improving approaches, such as space scanning, coordinate conversion, are introduced, and these approaches can also be applied to other kinds of radar/IR (non-imaging) dual mode seeker..
Infrared and Laser Engineering
- Publication Date: Aug. 01, 2002
- Vol. 31, Issue 4, 283 (2002)
Study on simulation of infrared decoy recognition Part 1: gray-scale time sequence analysis
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The infrared imaging characteristic difference between target and decoy is studied. It is pointed out that dynamic character is the main feature to distinguish target and decoy. At the stage of dot target, the variation magnitude of object's gray-scale intensity is regarded as the time sequence feature. Some methodThe infrared imaging characteristic difference between target and decoy is studied. It is pointed out that dynamic character is the main feature to distinguish target and decoy. At the stage of dot target, the variation magnitude of object's gray-scale intensity is regarded as the time sequence feature. Some methods such as multiresolution analysis and time-frequency analysis are adopted to identify target and decoy. The simulation result is given..
Infrared and Laser Engineering
- Publication Date: Aug. 01, 2002
- Vol. 31, Issue 4, 286 (2002)
Plane type object recognition based on revised 2D Fourier-wavelet descriptor
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A revised 2D Fourier-wavelet descriptor for the object recognition is proposed. The main revision lies in the process of transforming the object image into polar coordinate system. For the purpose of reducing calculating time and improving transforming precision, the redundant pixels in the image are deprived and the rA revised 2D Fourier-wavelet descriptor for the object recognition is proposed. The main revision lies in the process of transforming the object image into polar coordinate system. For the purpose of reducing calculating time and improving transforming precision, the redundant pixels in the image are deprived and the rest of them are fractionlized. Using a neural network classifier, this revised descriptor evidently reduces the calculating time and improves the rate of recognition in the experiment of plane type recognition. It is proofed to be a very effective method for feature description of object..
Infrared and Laser Engineering
- Publication Date: Aug. 01, 2002
- Vol. 31, Issue 4, 290 (2002)
Research on infrared small target detection technique based on bandpass filtering
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Infrared small target detection algorithm based on bandpass filtering is presented. The target imaging speciality is analyzed correctly, and the design method of bandpass filter is discussed. The target is confirmed by the correlation method based on position and gray after filtering process, and the calculation model Infrared small target detection algorithm based on bandpass filtering is presented. The target imaging speciality is analyzed correctly, and the design method of bandpass filter is discussed. The target is confirmed by the correlation method based on position and gray after filtering process, and the calculation model of sea-skyline is introduced. This method can properly restrain the interfere of sea and clouds, reduce the cost of computation, track the target in real-time, and can be implemented by hardware easily. It is very useful for the detection of small moving targets with low signal noise ratio..
Infrared and Laser Engineering
- Publication Date: Aug. 01, 2002
- Vol. 31, Issue 4, 294 (2002)
Study on reflecting characteristic of spacecraft for background radiation
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The main background radiation sources occured when spacecraft flys above aerosphere are introduced. The calculation method of the distribution of radiation intensity generated by the background radiation reflected by spacecraft is presented. Computer program is designed to calculate the distribution of radiation intensThe main background radiation sources occured when spacecraft flys above aerosphere are introduced. The calculation method of the distribution of radiation intensity generated by the background radiation reflected by spacecraft is presented. Computer program is designed to calculate the distribution of radiation intensity within 3～5μm and 8～14μm bands reflected by a taper shaped spacecraft flying above aerosphere at midday and midnight, and some reasonable results are obtained..
Infrared and Laser Engineering
- Publication Date: Aug. 01, 2002
- Vol. 31, Issue 4, 326 (2002)
Dual-wavelength ultra-short pulse generation by use of semiconductor laser diode
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An attractive alternative to generate tunable dual-wavelength pulses by external injection seeding of a gain-switched Fabry-Perot laser diode (FP-LD) is demonstrated. The external injection seeding branch consists of a FP-LD, a 3dB photo-coupler and two fiber Bragg gratings (FBG's). The dual wavelength can be selecAn attractive alternative to generate tunable dual-wavelength pulses by external injection seeding of a gain-switched Fabry-Perot laser diode (FP-LD) is demonstrated. The external injection seeding branch consists of a FP-LD, a 3dB photo-coupler and two fiber Bragg gratings (FBG's). The dual wavelength can be selected and their spacing can be tuned by adjusting two FBG's. The side-mode-suppression-ratio (SMSR) is better than 17dB over a 10nm wavelength tuning range. The whole system is simple and costs lower..
Infrared and Laser Engineering
- Publication Date: Aug. 01, 2002
- Vol. 31, Issue 4, 329 (2002)
Research on parameter optimization of laser strength processing for the slot bottom of shaft end
Analysis on inoculated cast iron HT300 surface layer microstrutures of non-transformation hardening, laser transformation hardening (LTH), laser shallow melting (LSM) and melting are presented by selecting different laser energy densities during laser strengthening treatment. And the processing for slot bottom of shaftAnalysis on inoculated cast iron HT300 surface layer microstrutures of non-transformation hardening, laser transformation hardening (LTH), laser shallow melting (LSM) and melting are presented by selecting different laser energy densities during laser strengthening treatment. And the processing for slot bottom of shaft end with laser transformation hardening are also discussed. The results show that laser transformation hardening treatment is satisfied the processing requirement. The optimization of laser processing parameters: laser power( P ), laser processing speck diameter( D ), and laser scanning velocity( V ) are obtained by taking a lot of experiments. The comparative results of hardness and abrasive resistance measurement show that hardness and absolute weared volume of HT300 samples processed by LTH/LSM are increased by 7%, 34% and decreased by 13%, 25% respectively than those of surface induction quenching. Practically LTH is simpler than other processing methods and the experimental results provide a reliable basis for processing the slot bottom surface of shaft end..
Infrared and Laser Engineering
- Publication Date: Aug. 01, 2002
- Vol. 31, Issue 4, 333 (2002)
Method of making true color hologram
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A method of composing true color hologram with rainbow holography under the condition of single-wavelength laser is proposed. It's main characteristic is that the tricolor information of color image is recorded through the technique of encoding with white light. The distinct merits of the method are effectively eliA method of composing true color hologram with rainbow holography under the condition of single-wavelength laser is proposed. It's main characteristic is that the tricolor information of color image is recorded through the technique of encoding with white light. The distinct merits of the method are effectively eliminating the effect of laser spots and then getting the true color hologram with low noise as well as high resolution.
Infrared and Laser Engineering
- Publication Date: Aug. 01, 2002
- Vol. 31, Issue 4, 338 (2002)
Hardware realization of real-time image fusion technology
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According to the practical demands of visual and long wave band infrared image fusion, a real-time realization technology based on the development of multi-channel and multi-sensor image pixel level fusion algorithm is presented. A real-time image fusion prototype system based on high speed DSP TMS320C62 is completed. According to the practical demands of visual and long wave band infrared image fusion, a real-time realization technology based on the development of multi-channel and multi-sensor image pixel level fusion algorithm is presented. A real-time image fusion prototype system based on high speed DSP TMS320C62 is completed. The design and simulation of a real-time image fusion system based on multi-DSP parallel architecture is developed..
Infrared and Laser Engineering
- Publication Date: Aug. 01, 2002
- Vol. 31, Issue 4, 342 (2002)
Information fusion for collectivity multi-sensor remote sensing image based on wavelet transform
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A method of information fusion for collectivity multi-sensor remote sensing image is presented based on wavelet transform. The disadvantages of traditional information fusion method on spatial resolution is improved. The original image is transformed into sub-image with wavelet transform and each sub-image is divided iA method of information fusion for collectivity multi-sensor remote sensing image is presented based on wavelet transform. The disadvantages of traditional information fusion method on spatial resolution is improved. The original image is transformed into sub-image with wavelet transform and each sub-image is divided into sub-blocks. The weighting value coeffients of high resolution images and low resolution images are computed according to collectivity square error rule, and then the high resolution image and low resolution image are fused and reconstructed. Afterwords, information fusion is made on both of the images with collectivity square error rule. Experimental results show that the method is workable to make low resolution image approaching high resolution image..
Infrared and Laser Engineering
- Publication Date: Aug. 01, 2002
- Vol. 31, Issue 4, 346 (2002)
Study on micro bulk defects detection in MEMS components
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The coherence of semiconductive material is an important assurance to realize the function of micro component. In order to detect micro bulk defects in silicic materials and MEMS components nondestructively, effectively and accurately, based on Generalized Lorenz-Mie Scattering theory, the scattering light intensity diThe coherence of semiconductive material is an important assurance to realize the function of micro component. In order to detect micro bulk defects in silicic materials and MEMS components nondestructively, effectively and accurately, based on Generalized Lorenz-Mie Scattering theory, the scattering light intensity distribution of the interaction between spherical defects and infrared laser beam in non-vertical direction, which aim at the physical property of silicic materials and MEMS components, is studied, and the mathematical simulation by computer is done. A new method to detect micro defect in MEMS components by analyzing back scattering light intensity distribution of infrared laser is presented. The basic principle and theoretic model of the detection is introduced, and the validity and feasibility of the method are proven by experiment..
Infrared and Laser Engineering
- Publication Date: Aug. 01, 2002
- Vol. 31, Issue 4, 351 (2002)
Design and application of a 3D measurement system for diagnosing parameters of the shape of surface
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The working process of the semiconductor photoelectric position sensitive device is analyzed. Using the continuous sending laser light source and semiconductor photoelectric position sensitive device, a high accurate tri-dimensional non-contact optical measurement system is designed. With the gridlines of the rectangulThe working process of the semiconductor photoelectric position sensitive device is analyzed. Using the continuous sending laser light source and semiconductor photoelectric position sensitive device, a high accurate tri-dimensional non-contact optical measurement system is designed. With the gridlines of the rectangular coordinate system located on the object being measured, the outline of the object is produced by this system, then it is applied to the measurement and diagnosis of multi-parameter of the irregular tri-dimensional object. Consisting of optical arrangement, this system is suitable for accurate measuring and detecting of the figures with irregular shape especially the edge shape. The tested datum has high value for studying and diagnosing the relationships of the skin lesion's format, character and type. The system will be used widely in the future..
Infrared and Laser Engineering
- Publication Date: Aug. 01, 2002
- Vol. 31, Issue 4, 356 (2002)
Crystal growth of MnxCd1-xIn2Te4 and its physical properties
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A diluted magnetic semiconductor MnxCd1-xIn2Te4( x =0.1) ingot is grown by ACRT-B method. Using scanning electron microscopy, X-ray powder diffractometer, ISIS energy-dispersive spectroscopy, Leica quantitative optical microscope and Fourier infrared spectrometer, the microstructure, morphology compositional distributiA diluted magnetic semiconductor MnxCd1-xIn2Te4( x =0.1) ingot is grown by ACRT-B method. Using scanning electron microscopy, X-ray powder diffractometer, ISIS energy-dispersive spectroscopy, Leica quantitative optical microscope and Fourier infrared spectrometer, the microstructure, morphology compositional distribution and transmittance properties of the ingot are analyzed. It is found that α, β and β_1 phases are at the tip of the Mn0.1 Cd0.9 In2Te4 ingot. Among them, α and β phases are formed during the growing process while β_1 is precipitated from α phase when temperature is below solidus. After the ingot is grown for 36mm, only β phase is formed. The morphology of β_1 phase varies from regular plates to irregular near-round blocks along the axis of the ingot from the beginning. The band gap of Mn0.1 Cd0.9 In2Te4 ingot is 1.2eV. Maximum of its near infrared transmittance in the range of 10000～2500cm -1 is up to 83% and its middle infrared transmittance in the range of 4000~500cm_1 is from 59% to 65%..
Infrared and Laser Engineering
- Publication Date: Aug. 01, 2002
- Vol. 31, Issue 4, 360 (2002)
Advances in cryogenic refrigerators for infrared sensing
As a supporting device of infrared detector, cryogenic refrigerator is a much-needed high-technique product used in military field. Our development work approaches the advanced world level. Critical techniques such as miniaturization, low vibration, long working life, fine flat wire fabrication, clearance sealing and eAs a supporting device of infrared detector, cryogenic refrigerator is a much-needed high-technique product used in military field. Our development work approaches the advanced world level. Critical techniques such as miniaturization, low vibration, long working life, fine flat wire fabrication, clearance sealing and electromagnetic interference eleminating, are mastered basically. Main specifications of Chinese-made linear motor resonant compressor are presented..
Infrared and Laser Engineering
- Publication Date: Aug. 01, 2002
- Vol. 31, Issue 4, 364 (2002)
[in Chinese]
Novel digital watermarking scheme using the wavelet transform
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With the rapid spread of computer networks and the further progress of multimedia technologies, copyright protection of digital media has been one of the most important issues in information technology field. A novel digital watermarking scheme using discrete wavelet transform is presented. The scheme embeds watermark With the rapid spread of computer networks and the further progress of multimedia technologies, copyright protection of digital media has been one of the most important issues in information technology field. A novel digital watermarking scheme using discrete wavelet transform is presented. The scheme embeds watermark in LL subband by modified Patchwork algorithm. The watermark signal can be extracted in decoding process without original image and can be rapidly remarked. The error probabilities of decode is reduced by exploiting BCH code. With the proposed algorithm, a meaningful watermark composed of 32 characters is embeded into image. Experimental results show that the watermark is perceptually invisible and the proposed scheme is robust to some image processing operations such as lossy JPEG defective compression, low pass filtering, median filtering..
Infrared and Laser Engineering
- Publication Date: Aug. 01, 2002
- Vol. 31, Issue 4, 297 (2002)
New approach to detect feature points of skeleton shape
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End points, corner points, branch points and crossing points are important feature points of skeleton shape. A new approach to detect these feature points is proposed. First, a method of the fast lookup table is taken to detect prepared feature points which include both of real and unreal feature points. Then, by clustEnd points, corner points, branch points and crossing points are important feature points of skeleton shape. A new approach to detect these feature points is proposed. First, a method of the fast lookup table is taken to detect prepared feature points which include both of real and unreal feature points. Then, by clustering these feature points and analyzing local structure, real feature points are obtained and unreal feature points are eliminated. The types of true feature points are identified and the quantative description of corner points is roughly given. The experiment results indicate that this method is easy of use and has high calculation speed. It plays an important role for some detection problems and character recognition..
Infrared and Laser Engineering
- Publication Date: Aug. 01, 2002
- Vol. 31, Issue 4, 301 (2002)
Extraction of straight line of image in paper based on run-length unit
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For the case of extracting straight line of image in paper, the definitions of run-length unit, central-run-length unit and maximum-adjacent-search area are given. An algorithm of extracting straight line of image in paper based on extraction and mergence of run-length unit is proposed. The experimental results and anaFor the case of extracting straight line of image in paper, the definitions of run-length unit, central-run-length unit and maximum-adjacent-search area are given. An algorithm of extracting straight line of image in paper based on extraction and mergence of run-length unit is proposed. The experimental results and analysis of algorithm complexity show that, comparing with methods based on Hough transform, the new method is simple and has excellent performance for extracting straight line of document form..
Infrared and Laser Engineering
- Publication Date: Aug. 01, 2002
- Vol. 31, Issue 4, 305 (2002)
Numerical algorithm for image segmentation based on variational method
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A mathematical model for image segmentation is presented. The link between Mumford-Shah's functional and image segmentation is discussed. As there is not an effective numerical method to solve this problem, a feasible algorithm for the variational problem in 1D is developed and then it is extended to 2D (image). A A mathematical model for image segmentation is presented. The link between Mumford-Shah's functional and image segmentation is discussed. As there is not an effective numerical method to solve this problem, a feasible algorithm for the variational problem in 1D is developed and then it is extended to 2D (image). A few experimental results proved the efficiency for the case of 1D and 2D..
Infrared and Laser Engineering
- Publication Date: Apr. 28, 2006
- Vol. 31, Issue 4, 310 (2002)
Skew document image detection based on Hough transform
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In the process of OCR image scanning, images are always placed slantwise to some extent. Such skew image may create difficulty to character segmentation and result to lower character recognition accuracy. In order to detect the skew angle of the images and correct them, a skew document image detection method based on HIn the process of OCR image scanning, images are always placed slantwise to some extent. Such skew image may create difficulty to character segmentation and result to lower character recognition accuracy. In order to detect the skew angle of the images and correct them, a skew document image detection method based on Hough transform is presented. To overcome the heavy computing of Hough transform, this method extracts "featured pixels" from the image. Experiment results show that skew angles of many kinds of document images can be efficiently and accurately detected by this method and the method has high adaptability..
Infrared and Laser Engineering
- Publication Date: Aug. 01, 2002
- Vol. 31, Issue 4, 315 (2002)
Filtering algorithm on underwater laser image stained by speckle noise
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Water is a special medium. In the underwater laser image there are always speckle noise which is caused by backscattering of water. A multidirectional morphological filtering algorithm is proposed by use of the characteristics of morphology's multisolution analysis and fastly-computing. It can not only efficiently Water is a special medium. In the underwater laser image there are always speckle noise which is caused by backscattering of water. A multidirectional morphological filtering algorithm is proposed by use of the characteristics of morphology's multisolution analysis and fastly-computing. It can not only efficiently reduce the speckle noise but also preserve the detailed features of the image. Experimental results indicate this algorithm is a fast efficient algorithm to filter speckle noise in the underwater laser image..
Infrared and Laser Engineering
- Publication Date: Aug. 01, 2002
- Vol. 31, Issue 4, 318 (2002)
Study on unequally spaced sampling parameters in rosette scanning imaging subsystem
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According to the characteristics of high/low scan frequency and dense/sparse scan tracks in central/fringing area of field of view of rosette scanning, a novel unequally spaced sampling method be used in rosette scanning infrared imaging subsystem is proposed to meet the reguirements of short processing time and good iAccording to the characteristics of high/low scan frequency and dense/sparse scan tracks in central/fringing area of field of view of rosette scanning, a novel unequally spaced sampling method be used in rosette scanning infrared imaging subsystem is proposed to meet the reguirements of short processing time and good image quality. The experimental results show that the optimum unequally spaced sampling function is gaussian. The relations among image data quantity, resolution and unequally spaced sampling parameters are discussed in detail and the method of parameter determination is consequently given..
Infrared and Laser Engineering
- Publication Date: Aug. 01, 2002
- Vol. 31, Issue 4, 322 (2002)
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