最新刊期
卷 ， 期 2 ， 2001
- 摘要：Mixed pixels constitutre AVHRR image. Evapotranspiration （ET） calculated based on AVHRR image certainly includes some errorous information of ground objects which have no meaning as far as ET is concerned. Registration of AVHRR image and high spatial resolution image is carried out. A meteorology-RS combination model is used to calculate the ET of the AVHRR image and that of the cropping area of the corresponding high resolution image respectively. The difference of these two ETs is given. The error is analysed and a corresponding statistical calibration method adaptable to the test region is given.关键词：evapotranspiration;high resolution;AVHRR
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发布时间：2021-06-10 - 摘要：Employing the Mueller matrix solution of random non-spherical particles, fully polarimetric scattering from heterogeneous canopy surfaces with 3-dimensional spatial structure is calculated. By using the ray tracing method, the scattering from all cells of scatters under a certain radar resolution is mapped into the image pixels. The radar images are simulated for different spatial structures such as number and density of trees, underlying land media, embedded target, etc. It is also compared with the AirSAR image for data validation and image physics.关键词：heterogeneous surface;polarimetric scattering;image simulation
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发布时间：2021-06-10 - 摘要：Airborne thermal scanner is capable of obtaining terrestrial temperature distribution with high resolution and efficiency. One of the essential parameters is signal to noise ratio （SNR）, which determines the final quality of thermal image. There are several factors such as emissivity, temperature, and scanning angle, which contribute to the SNR and in this paper, their influences on SNR have been theoretically analyzed and approaches of enhancing the SNR have been supplied. By using Gauss-Laguerre approximation method, the contributions of temperature, emissivity and scanning angle to the SNR have been studied and their mathematical expressions are presented. The theoretical estimation indicates that the emissivity has the highest influence on SNR and the scanning angle has the least one. The influence of scanning angle tends to lower the SNR and the value varies with angles. Laboratory measurement has been made, and the discrepancy between the theoretically computed and measured values of SNR is within the permissive error scope, considering the difference between conditions and that utilized to simulate.关键词：thermal infrared scanner;SNR;emissivity
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发布时间：2021-06-10 - 摘要：The processing of GPS/GLONASS data requires the specification of an observation model, which consisted of a functional and a stochastic model. The GPS/GLONASS functional model is already well known, but the GPS/GLONASS stochastic model is not. The stochastic model depends on not only the types of the observation and the receiver used, but also the environmental effects. To obtain the precisely combined GPS and GLONASS positioning, the importance of stochastic model of combined GPS and GLONASS observed value is analyzed. The posterior estimation method and iteration of variance and covariance method to estimate stochastic model using residuals of observable errors are proposed. The theoretical and numerical results show that the proposed method which can improve the reliability and precision of ambiguity resolution, is more rigorous in theory and more powerful in practice comparing with the stochastic model, Using iteration of variance and covariance method to estimate stochastic model of combined GPS and GLONASS observables is suggested.关键词：combined GPS and GLONASS;stochastic model;precise positioning
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发布时间：2021-06-10 - 摘要：In this paper, we proposed a new method for image feature extraction within scale space. The new method captures the relation of features between different scales, but not the features within a single scale space. Compared with the traditional methods, the proposed method can represent the scale property of texture better. In practice, we first construct a scalebased concurrent matrix （SCM） which reflects the relation between different scales; and then using the matrix calculate some useful measurements as the features for texture classification. Experiments also show that the proposed method can get more accurate results for texture classification than the traditional texture classification methods.关键词：concurrent matrix;scalebased concurrent matrix;frame wavelet;texture classification
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发布时间：2021-06-10 - 摘要：The traditional mosaic technology obtains fainted result by difference of geometry and color. This paper introduces mosaic technology of Digital Orthophoto Maps, the technology includes preprocess technology, mosaic technology, all mosaic flow chart and application. The preprocess technology includes color alteration, image match, Cross Area Correction, color alteration for altering the difference of color, and image match and Cross Area for altering the correction difference of geometry. The mosaic technology includes auto mosaicking, mosaicking by drawing a mosaic line, gray mosaicking, color mosaicking, mosaicking by drawing a mosaic line for mosaicking complex area by drawing a mosaic line, gray mosaicking, color mosaicking for eliminating the difference of geometry and color.关键词：digital orthophoto map;radiometric alteration;image match;overlapping area correction;automosaicking;mosaicking by drawing mosaic line
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发布时间：2021-06-10 - 摘要：The fundamentals of airborne laser remote sensing imaging technology is introduced first in this paper. As a key part of the technology, the waveform digitizing circuit for acquiring laser return of ground targets is designed and its features are discussed. Then how to control digitizing and how to store digitized data are described. Finally some problems about preprocessing of digitized data are discussed and some typical results are given. The preprocessed results will be used as data sources to directly produce 3D image and to sort ground objects.关键词：waveform digitization;airborne remote sensing;airborne imaging;laser imaging;airborne laser sounding
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发布时间：2021-06-10 - 摘要：Airborne 3D imager which integrates global positioning system, attitude measurement unit, scanning laser range finder and spectral imager can produce geo-referenced image and digital terrain models （DTM） without ground control points. The raw image is rectified based on the laser points with known coordinates. Owning to the existence of the error, the geo-referenced images of neighbor strips can not be mosaiced seamlessly. Therefore, it is necessary to eliminate the error. The error source of each component of 3D imager such as GPS error, attitude error and laser range error is analyzed and the system error between the components is also described. Then we focus on the error processing algorithm. The system error is determined and corrected using least mean gray difference in the overlap and the random error is processed by variant weight algorithm in order to mosaic the strips. The test result proves that the error processing methods is feasible.关键词：D imager;system error;strips mosaic
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发布时间：2021-06-10 - 摘要：The correlation of HRIS spectral image sequence was analyzed in this paper. A lossless compression algorithm based on D+2PCM coder, which reduced the spectral and spatial correlation, has been developed. The proposed method depressed the image redundancy sufficiently, and increased compression ratio and efficiency. The results of experiments prove it practicable and fast.关键词：spectral correlation;spatial correlation;DPCM;D+2PCM;Lossless compression
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发布时间：2021-06-10 - 摘要：The Classification of remotely sensed data is the main theme of Remote Sensing Image Understanding and Analysis, while the artificial neural networks （ANN） is one of the latest and most important techniques developed recently in the area of connective artificial intelligence. In this paper, after we made a through study on the structure of the multilayer perceptron （MLP） and deeply analyzed it’s backpropagation （BP） training algorithm, the framework of how to integrate Geoknowledge with ANN and apply to RS classification is put forward. Firstly, the suggestions of improving the efficiency of BP algorithm, including network architecture selection, use of optimization on learning rate, and assistance with additional data and expert knowledge etc., are presented. Then, after the general approach of ANN based RS image classification is reviewed, the model of integrating Geoknowledge with ANN for RS image classification is developed with specific experiment of RULE based MLP. Experimental result shows significant improvement in comparison with statistical and traditional ANN classifiers.关键词：artificial neural networks （ANN）;multilayer perceptron （MLP）;BP algorithm;RS image classification;geoknowledge
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发布时间：2021-06-10 - 摘要：Based on the multiresolution wavelet analysis technique, a study of the image data fusion of Liao Dong Bay sea ice including NOAA/AVHRR and Radarsat/ScanSAR data was carried out in this paper. The results were analyzed and discussed. The multilevel decomposition and reconstruction techniques of wavelet transform were applied for the first time in the processing of image data fusion.关键词：image data fusion;sea ice remote sensing;wavelet transform;multiresolution analysis;multilevel decomposition and reconstruction
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发布时间：2021-06-10 - 摘要：Lacking analytical and modelling functions is widely recognized as a major deficiency of currently available GIS. Model Base System being put forward in recent years is aimed at providing powerful functions such as model management and analysis. Model Base System can be utilized to classify and maintain various models, and support their generaltion, storage, query, management and analysis.;Current research on MBS is primarily focused on specific application fields, and such systems can only be used in their specific fields. When faced with other fields, those systems need large modifications or to be developed from scratch. An economical and flexible way is to develop a general platform of MBS which experts in various fields can use to build their own model bases efficiently. In this case, we designed and developed an Osprey Model Base System General Platform. Its architecture is put forward, and the schemes of some critical techniques of the platform such as model dictionary, data interface and model-creating techniques are presented in detail. Then the main functions of the platform are outlined.;In National High-Tech Project 863-07, we built MBS for Marine Fishery Services efficiently on the Osprey Model Base System General Platform. This success demonstrates that the idea of the MBS platform is feasible. An example of model analysis-Virtual Population Analysis is also presented.关键词：model base system general platform;Spatial decision support system;model base management system;model base;model dictionary;marine fishery services
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发布时间：2021-06-10 - 摘要：Land cover change is a important effect on carbon cycle. In order to estimate changes in carbon pools and fluxes to the atmosphere, we used Landsat TM data of 1992 and 1996 to calculate the extent of different land cover types and their change to each other in the estuary area of Yellow River delta. Image processing and unsupervised classification allowed the production of accurate land cover maps of 1992 and 1996, and then the changes were detected. Estimation of carbon pools and fluxes to the atmosphere was carried out using the results of Landsat image analysis and published data about carbon stocks in vegetation and soil. The results showed that the vegetation carbon reserves was 11.43×10+5t, the soil carbon reserves was 7.24×10+6t in 1992, while the area of forest increased 146.76×10+2hm+2, and the vegetation carbon reserves increased 7.43×10+5t during the four years from 1992 to 1996. So the land cover change lead to an increasing in carbon reserves in this area. It is a carbon pools in the global change progress.关键词：Yellow River delta;land cover change;carbon cycle
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发布时间：2021-06-10 - 摘要：Information about ship movement on water surface is one of the important detected objects in many fields such as water carriage engineering and military. In this paper, two indirect methods for the estimation of a moving ship’s speed by using remote sensing techniques are discussed because there is a close relation between static characteristics of ship wake and ship speed. To extract ship speed, one method is about using wave height spectra information of ship wake, and other method about using transverse wave information of ship wake. After the theory of these two methods is introduced, a scheme about extraction of a ship’s speed by using remote sensing techniques is described and these two methods are validated by using simulated and observed ship wake wave height data. It can be seen from the calculated results that both the two methods meet the requirement of people who need to know only magnitude of ship speed and error of the method on using wave height spectra to extract ship speed. The study shows a new method to real-timely or nearly real-timely detect the speed of a moving ship and has good perspective on its applications in the fields of enhancing ship management ability, military monitoring ability, and attacking military objects ability.关键词：remote sensing techniques;ship;ship wake;ship speed
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发布时间：2021-06-10 - 摘要：According to the multi-temporal NOAA/AVHRR imagery and near simultaneously acquired in-situ surface-layer sediment data, this paper uses 3 kinds of parameter, i.e. the gray values of the imagery, the slope of R-1-R-2 relative curve, and the sediment index to establish the quantitative retrieval models for sediment’s concentration respectively, and to assess their application effects.;The correlation of the model obtained from the gray value method, for using only the spectral information of one band, is not very good; The slope method corrects the atmospheric affection by computing the R-1-R-2 relative curve, and the model from it is stable. While, the sudden change of the slope value often happens in the interface of the water of different sediment’s concentration, which will affect the result. The sediment index method uses the spectral information of Ch1 and Ch2, a good quantitative model and imagery with plenty of sediment information are derived.关键词：satellite remote sensing;quantitative retrieval model;gray value;slope;sediment index
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发布时间：2021-06-10
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