Journals >Infrared and Laser Engineering
Contents
2003
Volume: 32 Issue 2
27 Article(s)
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Research Article
Trend of laser radar for military
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The trend of laser radar for military is discussed, which includes the new laser radar system (the phased array laser radar, the imaging laser radar for ATR, the MTI laser radar, the synthetic aperture laser radar and the scannerless imaging laser radar), the long-distance application of laser radar, the integration ofThe trend of laser radar for military is discussed, which includes the new laser radar system (the phased array laser radar, the imaging laser radar for ATR, the MTI laser radar, the synthetic aperture laser radar and the scannerless imaging laser radar), the long-distance application of laser radar, the integration of multi-sensor and multi-function incorporation, the wide application of DPL and OPO in laser radar..
Infrared and Laser Engineering
- Publication Date: Apr. 01, 2003
- Vol. 32, Issue 2, 111 (2003)
Performance analysis of direct detection Doppler lidar for wind measurement
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The principles of lidar wind measurement are reviewed and compared. The method of direct detection with a Fabry-Perot interferometer for 3D wind measurement is proposed. The measurement principle is described and the performance and measurement error of a lidar system is analyzed. Then, the accuracy of the lidar based The principles of lidar wind measurement are reviewed and compared. The method of direct detection with a Fabry-Perot interferometer for 3D wind measurement is proposed. The measurement principle is described and the performance and measurement error of a lidar system is analyzed. Then, the accuracy of the lidar based on the molecular backscattering is compared with that on aerosol backscattering. The proposed lidar system with Rayleigh backscattering is given for the 3D wind measurement..
Infrared and Laser Engineering
- Publication Date: Apr. 01, 2003
- Vol. 32, Issue 2, 115 (2003)
Development and application of the pulsed LD rangefinder
The pulsed LD rangefinder has many characteristics, such as simple construction, small size, light weight and so on. It has some advantages in applications of short and middle range measurement. At present, the maximum measurement range is about 1 km, and the minimum resolution is about several centimeters. The researcThe pulsed LD rangefinder has many characteristics, such as simple construction, small size, light weight and so on. It has some advantages in applications of short and middle range measurement. At present, the maximum measurement range is about 1 km, and the minimum resolution is about several centimeters. The research on pulsed LD rangefinder started in 1960's and in the middle of 1980's a series of key techniques had been solved. In the midde of \{1990's\} some kinds of product had been developed. It can be expected that in near future the number of the product will increase rapidly in very wide areas. In this paper, the development and application of pulsed LD rangefinder around the world are presented, and several typical applications are demonstrated..
Infrared and Laser Engineering
- Publication Date: Apr. 01, 2003
- Vol. 32, Issue 2, 118 (2003)
Measurement on time-interval in pulsed laser ranging and error analysis
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The traditional digital counting method for time-interval measurement in pulsed laser ranging can't achieve high precision, for it's restricted by the frequency of counting clock. Analog interpolation time-interval measurement has advantages of long measurement range, good linearity and high precision, so it isThe traditional digital counting method for time-interval measurement in pulsed laser ranging can't achieve high precision, for it's restricted by the frequency of counting clock. Analog interpolation time-interval measurement has advantages of long measurement range, good linearity and high precision, so it is widely applied for time-interval measurement in pulsed laser ranging. The principle of time-interval measurement by analog interpolation in pulsed laser ranging is introduced. The corresponding time-interval measurement system is designed and studied in experiments. The precision of time-interval measurement reaches up to 100 ps, which corresponds to distance measurement precision at 1.5 cm. In the end, the error of analog interpolation time-interval measurement is analyzed theoretically..
Infrared and Laser Engineering
- Publication Date: Apr. 01, 2003
- Vol. 32, Issue 2, 123 (2003)
Method of simulated testing of pulse laser rangefinder
The method of simulated test of pulse laser rangefinder uses LED (or LD) to simulate object to test pulse laser rangefinder (or ranging equipment). The test system receives a laser beam generated by rangefinder and starts a precision time delay. Then it feeds back an (one to three) "object pulses" to the rangThe method of simulated test of pulse laser rangefinder uses LED (or LD) to simulate object to test pulse laser rangefinder (or ranging equipment). The test system receives a laser beam generated by rangefinder and starts a precision time delay. Then it feeds back an (one to three) "object pulses" to the rangefinder tested and begins another time delay (twice) at the moment of the timing ends. Whether the rangefinder works normally by observing the display of the rangefinder and the laser energy the rangefinder emitted at the same time is measured. By this method, the online test of the pulse laser rangefinder becomes possible..
Infrared and Laser Engineering
- Publication Date: Apr. 01, 2003
- Vol. 32, Issue 2, 127 (2003)
Comparison of algorithms for suppressing speckle in laser imaging system
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The coherent CO2 laser imaging system has high resolution, strong anti-interference and 3D imaging, but its imagery is usually affected by speckle noise, imaging resolution descend. It's important to study on suppressing speckle algorithms for this system. In the paper, three common algorithms——median filtering, hoThe coherent CO2 laser imaging system has high resolution, strong anti-interference and 3D imaging, but its imagery is usually affected by speckle noise, imaging resolution descend. It's important to study on suppressing speckle algorithms for this system. In the paper, three common algorithms——median filtering, homomorphic mean filtering, and Lee filtering were introduced and used in suppressing speckle in coherent pulse CO2 laser imaging system. Then these algorithms were compared. The results show that non-iterative Lee filtering with small windows is better. The speckle noises are suppressed clearly, and image edges are maintained..
Infrared and Laser Engineering
- Publication Date: Apr. 01, 2003
- Vol. 32, Issue 2, 130 (2003)
Experimental research on the influence of heating effect of window on quality of high energy laser beam
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CaF\-2 was chosen as the window material. The experiment was guided to test the influence of the window on beam quality while the window was at high temperature and stress. A deterioration of high energy laser beam quality caused by temperature rise and deformation of CaF2 window was presented in our experiment. After CaF\-2 was chosen as the window material. The experiment was guided to test the influence of the window on beam quality while the window was at high temperature and stress. A deterioration of high energy laser beam quality caused by temperature rise and deformation of CaF2 window was presented in our experiment. After the far-field beam spot of high energy laser is analyzed, and the far-field beam spot's radius increase rapidly owing to the heating effect of CaF2 window is shown. Therefore, the influence of heating effect of CaF2 window on beam quality is verified..
Infrared and Laser Engineering
- Publication Date: Apr. 01, 2003
- Vol. 32, Issue 2, 134 (2003)
Parameter calculation of seed injected oscillator in copper vapor laser
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The characteristics of seed injected oscillator consisting of main oscillator and power amplifier are analyzed by matrix optics theory. The main oscillator consists of two spherica mirrors of curvature -250 mm and 5 000 mm, spaced 2 375 mm apart. The power amplifying cavity consists of two spherica mirrors of curvatureThe characteristics of seed injected oscillator consisting of main oscillator and power amplifier are analyzed by matrix optics theory. The main oscillator consists of two spherica mirrors of curvature -250 mm and 5 000 mm, spaced 2 375 mm apart. The power amplifying cavity consists of two spherica mirrors of curvature 400 mm and 5 600 mm, spaced 3 000 mm apart. The full beam divergence of the oscillator output is about scores of μrad, which can satisfy the requirements of MOPA technology in copper vapor laser..
Infrared and Laser Engineering
- Publication Date: Apr. 01, 2003
- Vol. 32, Issue 2, 138 (2003)
Investigation on mechanisms of laser diode ignition
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Thermal interaction mechanism of laser diode ignition is investigated through theoretic analysis, experiments and numerical calculations. The critical values and impacting factors are analyzed. In general, the mechanism of laser diode ignition upon energetic materials is thermal interaction, and laser power density hasThermal interaction mechanism of laser diode ignition is investigated through theoretic analysis, experiments and numerical calculations. The critical values and impacting factors are analyzed. In general, the mechanism of laser diode ignition upon energetic materials is thermal interaction, and laser power density has significant impact on ignition..
Infrared and Laser Engineering
- Publication Date: Apr. 01, 2003
- Vol. 32, Issue 2, 141 (2003)
Experimental investigation of the change of semiconductor laser output wavelength corresponding to operation current
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Two kinds of semiconductor lasers (InGaAs, 2 W, continuous output, infrared 980 nm and InGaAsP, 120 mW, continuous output, infrared 980nm, including tail-fiber and cooler) are taken for examples and the rules of the change of semiconductor lasers output wavelength correspondig to operation current are experimentally inTwo kinds of semiconductor lasers (InGaAs, 2 W, continuous output, infrared 980 nm and InGaAsP, 120 mW, continuous output, infrared 980nm, including tail-fiber and cooler) are taken for examples and the rules of the change of semiconductor lasers output wavelength correspondig to operation current are experimentally investigated. The results show that the emission wavelength of the laser shifts in the direction of long wavelength as the operation current rises. The slopes are approximately 0.374 nm/100 mA and 0.220 nm/10 mA, respectively. Furthermore, the change of wavelength becomes more obvious while laser works in large current..
Infrared and Laser Engineering
- Publication Date: Apr. 01, 2003
- Vol. 32, Issue 2, 144 (2003)
Algorithm of infraredbackground suppression and small target detection
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It is an important task to detect and track the lowly observable and small targets in a sequence of infrared images against cloudy background. A simple and practical scheme about dim small target detection in cloudy background is given. In this scheme, the first step is to suppress the background clutter to obtain the It is an important task to detect and track the lowly observable and small targets in a sequence of infrared images against cloudy background. A simple and practical scheme about dim small target detection in cloudy background is given. In this scheme, the first step is to suppress the background clutter to obtain the higher SNR of the images. The second step is to segment the image using a threshold to get a binary image. According to the movement continuity of targets in temporal and spatial domain, these targets are identified by a pipeline method. The experimental results prove that the algorithm is very effective..
Infrared and Laser Engineering
- Publication Date: Apr. 28, 2006
- Vol. 32, Issue 2, 148 (2003)
Detection algorithm for infrared small target in background of sea and sky
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The small target detection in infrared imagery with complex background of sea and sky is studied. Taking into account that small target of infrared image guidance like naval vessel is always nearby the sea-sky-line, wavelet multiresolution edge detection algorithm is adopted to detect the sea-sky-line. The potential taThe small target detection in infrared imagery with complex background of sea and sky is studied. Taking into account that small target of infrared image guidance like naval vessel is always nearby the sea-sky-line, wavelet multiresolution edge detection algorithm is adopted to detect the sea-sky-line. The potential target area can be decided subsequently, then the target is found by careful search in this area. Therefore, a new algorithm for small target detection from coarse scale to elaborate scale is proposed. Experimental results indicate that the method can detect and locate small targets precisely in infrared image obtained in conventional noise conditions. The correct detection ratio of single image is more than 96%, and this method has high detection ratio from a single image and high speed..
Infrared and Laser Engineering
- Publication Date: Apr. 01, 2003
- Vol. 32, Issue 2, 153 (2003)
Moving point targets detection based on the infinite norm of the discontinuous frame difference vector
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A mathematical model to detect the moving targets by the discontinuous frame difference vector's infinite norm is proposed. Then the parallel processing construction system is established, which can make full use of the moving point targets detection ability of the discontinuous frame difference vector's infiniA mathematical model to detect the moving targets by the discontinuous frame difference vector's infinite norm is proposed. Then the parallel processing construction system is established, which can make full use of the moving point targets detection ability of the discontinuous frame difference vector's infinite norm. Due to the algorithm is based on the discontinuous frame difference, the parallel processing system can detect not only the moving point targets whose displacement is no less than one pixel between two continuous frames, but also the moving point targets whose displacement is no more than one pixel between two continuous frames but larger than one pixel between two discontinuous frames. Therefore, the ability of detecting and recognizing the moving point targets is highly improved. The experimental result shows that the algorithm is efficient..
Infrared and Laser Engineering
- Publication Date: Apr. 01, 2003
- Vol. 32, Issue 2, 157 (2003)
Radon transform for line segment detection in low SNR image
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Radon transform has important value in mathmatics theory, which can be used in algorithms for detecting linear features in an image. However, it has difficulty in detecting line segments in image, because Radon transform can not provide information about the positions of endpoints and the length. These problems become Radon transform has important value in mathmatics theory, which can be used in algorithms for detecting linear features in an image. However, it has difficulty in detecting line segments in image, because Radon transform can not provide information about the positions of endpoints and the length. These problems become more serious when the transform is applied to an image with a high level of noise. The algorithm's suitability is discussed for linear feature detection in low SNR image, and this algorithm's advantages and drawbacks are analyzed. Then an accessional strategy based on information fusion is put forward to remedy the drawbacks. Aiming at low SNR image of airdrome's runway, the new algorithm reveals the preferable performance of speed and location..
Infrared and Laser Engineering
- Publication Date: Apr. 01, 2003
- Vol. 32, Issue 2, 163 (2003)
Image gray calibration based on histogram correlation
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For analyzing land covers and matching of remote sensing images, gray calibration of image is an indispensable part, for the result will directly influence the later procession. An algorithm of image gray calibration based on histogram correlation with linear point operations is put forward in three steps. Firstly, solFor analyzing land covers and matching of remote sensing images, gray calibration of image is an indispensable part, for the result will directly influence the later procession. An algorithm of image gray calibration based on histogram correlation with linear point operations is put forward in three steps. Firstly, solve the slope ratio by making histogram of image for calibrating and expecting consistency. Secondly, solve the amount of shift by histogram correlation. Thirdly, realize gray calibration by using linear point operations. The result shows that the method has better stability for gray changing caused by illumination..
Infrared and Laser Engineering
- Publication Date: Apr. 01, 2003
- Vol. 32, Issue 2, 167 (2003)
Fusion of low light level image and laser assistant vision image based on contrast modulation
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Low light level (LLL) image procession has become one of the most important task of low light level night vision technology. Image fusion is a newly developing technology which extracts information from multi-channel images to form a more understandable one for the use of observer of decision making system. The laser aLow light level (LLL) image procession has become one of the most important task of low light level night vision technology. Image fusion is a newly developing technology which extracts information from multi-channel images to form a more understandable one for the use of observer of decision making system. The laser assistant vision infrared image is obtained by use of infrared laser assistant vision technology. The features of LLL image and laser assistant vision image are different, because the spectrums they respond are different. The fusion of these two kinds of image is realized based on contrast modulation using wavelet transform. The experimental results show that the fusion of laser assistant vision image and LLL image can effectively improve the of quality image. This technology can increase the war field information from the LLL night vision system and extend the detection distance of the LLL imaging system effectively..
Infrared and Laser Engineering
- Publication Date: Apr. 01, 2003
- Vol. 32, Issue 2, 170 (2003)
Study on image fusion based on different fusion rules of wavelet transform
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Image fusion is one of the important techniques to enhance image information. A novel pixel-level image fusion scheme is presented based on multiscale decomposition. The wavelet transform is used to construct the wavelet coefficients of fused image using multiple operators according to different fusion rules. ComparisoImage fusion is one of the important techniques to enhance image information. A novel pixel-level image fusion scheme is presented based on multiscale decomposition. The wavelet transform is used to construct the wavelet coefficients of fused image using multiple operators according to different fusion rules. Comparison of fusion results of visible image and infrared image is given. It shows that the proposed method based on local area energy of each pixel can achieve better fusion performance than other usual fusion rules, avoiding losing information and improving the resolution and the special quality of image. Then the fused image is more suitable for human vision or machine perception..
Infrared and Laser Engineering
- Publication Date: Apr. 01, 2003
- Vol. 32, Issue 2, 173 (2003)
Overview of wavelet-analysis-based image fusion
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The objective of image fusion is to combine information from multiple images of the same scenc to accomplish tasks that cannot be achieved with a single image or source. Wavelets with their multiresolution property, have been proved to be effective in the integration of the coarse features and finer resolution details The objective of image fusion is to combine information from multiple images of the same scenc to accomplish tasks that cannot be achieved with a single image or source. Wavelets with their multiresolution property, have been proved to be effective in the integration of the coarse features and finer resolution details of these images to produce a well fused image. This paper surveys methods and principle of wavelet-based image fusion, pays attention to advantages of wavelet-based image fusion, and compares the characteristics of different image fusion rules. Furthermore, wavelet-packet-based, wavelet-frame-based and multiwavelet-based image fusion methods are presented..
Infrared and Laser Engineering
- Publication Date: Apr. 01, 2003
- Vol. 32, Issue 2, 177 (2003)
Mathematical analysis of course tracking control and pose aberration correction
In the scene matching system, the axis of camera is looking-down. For the limit of the interspace the camera is in strap-down way with carrier in pitch and the rolling direction. In this way, only the y-axis of the ground image accords with geography coordinate, and there is distortion from pitch and rolling attitude. In the scene matching system, the axis of camera is looking-down. For the limit of the interspace the camera is in strap-down way with carrier in pitch and the rolling direction. In this way, only the y-axis of the ground image accords with geography coordinate, and there is distortion from pitch and rolling attitude. Before images matching, correction is needed. Mathematical relation of adjustment angle α of course tracking control and attitudes (φ,,γ) and formulae of correction of the distortion are given..
Infrared and Laser Engineering
- Publication Date: Apr. 01, 2003
- Vol. 32, Issue 2, 182 (2003)
Real time geometric rectification algorithm by system of movement along with odd axes base on C6201
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Real time image photographed by aerocraft is processed in short time and small program memory. Improved geometric calibration algorithm by increment is proposed. Convergent function is deployed by use of Taylor progression based on TMS320C6021 DSP. In the way, error accords with requirement of system. Parameters of geoReal time image photographed by aerocraft is processed in short time and small program memory. Improved geometric calibration algorithm by increment is proposed. Convergent function is deployed by use of Taylor progression based on TMS320C6021 DSP. In the way, error accords with requirement of system. Parameters of geometric calibration algorithm are optimized by the feature of orthodox matrix. Time and memory accord with real time system..
Infrared and Laser Engineering
- Publication Date: Apr. 01, 2003
- Vol. 32, Issue 2, 186 (2003)
Solvation of electron trajectory by kinetic equation method in image tube
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Kinetic equation was used to solve electron trajectoy. By utilizing 64-point-Lagrange-interpolation and spherical cathode extrapolation, potential of random point in space was solved. Then by using changing-step Runge-Kutta method, electron trajectory was solved. Typical electron trajectory of the concentric spherical Kinetic equation was used to solve electron trajectoy. By utilizing 64-point-Lagrange-interpolation and spherical cathode extrapolation, potential of random point in space was solved. Then by using changing-step Runge-Kutta method, electron trajectory was solved. Typical electron trajectory of the concentric spherical system was computed. Compared with the ideal datum, its accuracy reaches 10-3..
Infrared and Laser Engineering
- Publication Date: Apr. 01, 2003
- Vol. 32, Issue 2, 191 (2003)
Improvement and development of all-optical wavelength conversion technologies
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All-optical wavelength conversion (AOWC) technologies are very important for the development of WDM optical networks. After the conventional AOWC is reviewed, the basic principles of three new-type AOWC technologies are described repectively. Their experimental results and characteristics are introduced. Furthermore, tAll-optical wavelength conversion (AOWC) technologies are very important for the development of WDM optical networks. After the conventional AOWC is reviewed, the basic principles of three new-type AOWC technologies are described repectively. Their experimental results and characteristics are introduced. Furthermore, the research direction of AOWC is discussed briefly..
Infrared and Laser Engineering
- Publication Date: Apr. 01, 2003
- Vol. 32, Issue 2, 195 (2003)
Measurement of motion parameters based on the binocular vision model
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A method based on binocular vision model is discussed to determine the relative motion parameters between two space objects. The relationship between the detection of feature points and the measurement of motion parameters is studied in this instance of ignoring the camera calibrate errors. By analyzing the measurementA method based on binocular vision model is discussed to determine the relative motion parameters between two space objects. The relationship between the detection of feature points and the measurement of motion parameters is studied in this instance of ignoring the camera calibrate errors. By analyzing the measurement error of center of figure of the feature point affected by image segmentation, an algorithm based on iteration of the center of the track window is used to improve the measurement accuracy. The experiment verifies that the algorithm is valid..
Infrared and Laser Engineering
- Publication Date: Apr. 01, 2003
- Vol. 32, Issue 2, 199 (2003)
Interferogram acquisition and procession system based on Windows environment
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An interferogram acquisition and procession system is introduced in detail. The system based on Windows98 environment is designed for V3A image grabber. It mixes the advanced image acquisition and procession technology and database technology together. It has many features, such as compact structure,reliability, variouAn interferogram acquisition and procession system is introduced in detail. The system based on Windows98 environment is designed for V3A image grabber. It mixes the advanced image acquisition and procession technology and database technology together. It has many features, such as compact structure,reliability, various functions, real time performance, friendly interface and easy use. The design of interferogram database makes the monitoring of equipment condition convenient, so the testing efficiency is improved..
Infrared and Laser Engineering
- Publication Date: Apr. 01, 2003
- Vol. 32, Issue 2, 203 (2003)
Design for serial communication of master/slave computer based on VB
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Serial communication plays an essential role in data acquisition system. It is convenient and efficient to realize serial data communication by using communication control of VB\{6.0\}, comparing with other programming methods. Serial data communication system for LED displaying between PC and multi-microcomputer is deSerial communication plays an essential role in data acquisition system. It is convenient and efficient to realize serial data communication by using communication control of VB\{6.0\}, comparing with other programming methods. Serial data communication system for LED displaying between PC and multi-microcomputer is designed through the collaboration of parity-bit of 8250 and SM\-2 of 8031. The flow chart and some programming skill based on VB6.0 are introduced in detail. The confliction between communication mode 0 and mode 1 is solved when they are used simultaneously. The experimental result shows that easy and practical design can increase the efficiency of system design..
Infrared and Laser Engineering
- Publication Date: Apr. 01, 2003
- Vol. 32, Issue 2, 207 (2003)
Fast algorithm for MPEG video segmentation based on macroblock type information
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A fast algorithm for MPEG compressed video segmentation based on macroblock(MB) types is presented. A rough scan over the P-frames locates the potential scene change boundaries and the solution is then refined by a precise scan over the B-frames of the respective neighborhoods. The advantages of this algorithm are its A fast algorithm for MPEG compressed video segmentation based on macroblock(MB) types is presented. A rough scan over the P-frames locates the potential scene change boundaries and the solution is then refined by a precise scan over the B-frames of the respective neighborhoods. The advantages of this algorithm are its direct extraction from the MPEG bitstreams after VLC decoding, rule-based detection, frame-based detection accuracy and high detection speed..
Infrared and Laser Engineering
- Publication Date: Apr. 01, 2003
- Vol. 32, Issue 2, 211 (2003)
Design of storage scheme for SI in DVB systems
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With the development of digital TV technology, the ability of receiver to receive the service information in TS becomes more and more important. Firstly the PSI (Program Specific Information) in MPEG-2 and SI (Service Information) in DVB (Digital Video Broadcasting) are analyzed. Then a storage scheme for SI in DVB sysWith the development of digital TV technology, the ability of receiver to receive the service information in TS becomes more and more important. Firstly the PSI (Program Specific Information) in MPEG-2 and SI (Service Information) in DVB (Digital Video Broadcasting) are analyzed. Then a storage scheme for SI in DVB systems is presented. In this scheme, SI can be stored, retrieved, extracted and updated in real time and multitask environment. As data can be shared between PSI and SI, the requirement of the hardware resources is greatly reduced..
Infrared and Laser Engineering
- Publication Date: Apr. 01, 2003
- Vol. 32, Issue 2, 217 (2003)
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