最新刊期
卷 ， 期 2 ， 2005
- 摘要：This paper briefly reviewed the significant achievements on geological remote sensing in China in the 20th century, and illustrated four momentous breakthroughs: plate tectonic demonstration and linear style analysis, digital geology and ore prospecting, the discovery of quaternary geology and geomorphology, routes selection and sites selection of engineering geology. The paper indicated the new tasks of land resources investigation in the 21st century. There are urgently needs for intensifying the research on remote sensing information mechanism, information fusion and sharing, interdiscipline, capabilities of socio-economic statistical and spatial analysis, and attention on moon-probing plan and remote sensing mapping.关键词：geological remote sensing;land resources investigation
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发布时间：2021-06-10 - 摘要：Leaf area index （LAI） is an important parameter for describing vegetation canopy structure in the terrestrial ecosystem. LAI can be obtained using spectral information such as simulated relation of VI（ vegetation index） , however, many VIs are affected by soil. For row crop, it is difficult to remove the effect of soil, and the error is large using the method of VI. Multiangular remote sensing is capable of providing more three-dimensional information of vegetation, and it is powerful in obtaining the parameter of the plants. However, currently, the retrieval of multiangular remote sensing seldom considers the use of spectral information. We use MSAVI2 as an index to get the a priori knowledge of LAI. As a result, the a priori knowledge is more objective. From the comparison of using or not using this MSAVI predicted a priori knowledge, we found that this approach is effective.关键词：leaf area index;inversion;row crop;Multiangular;multispectral;the analysis of uncertainty and sensibility
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发布时间：2021-06-10 - 摘要：It is generally recognized that Case 2 waters are more complex than Case 1 waters in their composition and optical properties. The standard algorithms （usually band ratio） in use today for chlorophyll retrieval from spectral data break down in Case 2 waters. Hyperspectral ocean color sensing may be necessary for Case 2 waters’ constituents retrieval. However, hyperspectral data are usually highly correlated and statistical algorithms such as principal component inversion have been employed in ocean color sensing. In the present paper the principle, algorithm and advantage of another statistical algorithm-partial least squares regression （PLS） are briefly described. Then PLS is applied to the retrieval of oceanic color constituents from China Yellow Sea and South China Sea field reflectances, which are typical of Case 2 waters. Cross-validation of PLS analysis shows that the retrieval accuracy is good and the predicted relative error of chlorophyll-a is less than 37% . In order to check the robusticity of the PLS inversion model, PLS is also applied to the retrieval of oceanic color constituents from computed reflectances to which 5% noise is added randomly. The cross-validation results of PLS analysis on simulated data show that the model is robust and the predicted relative error of the three components （chlorophyll-a, Total Suspended Matter and Yellow Substance） is less than 5%. Pre-processing of data is essential for the constituents’ concentration ranging over several magnitudes. As an empirical algorithm, the training data set for PLS should be typical that the data points distribute uniformly in the concentration range. It is suggested that PLS be suitable for the regression problems which have a few observations but a lot of spectra variables, e. g. the retrieval of oceanic color constituents from Case 2 water reflectance.关键词：case Ⅱ water spectra;oceanic color constituents’ retrieval;partial least squares regression
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发布时间：2021-06-10 - 摘要：The existence of mixed pixels is the main factor influencing the classification accuracy of remotely sensed image. Fuzzy classification is an important method of unmixing the mixed pixels. Its results depend on how accurate the membership value to various types of each pixel after classification corresponds to its actual component. If the clustering number is not equal to the actual type number in the unsupervised classification, or there are some types untrained in the supervised classification, the accuracy of the popular algorithm, namely Fuzzy c-means （FCM） will be degraded. Fortunately, Possibilistic c-means （PCM） is insensitive to it and can work well. This paper proposes the pixel unmixing method of remotely sensed image based on PCM algorithm. The priority of the PCM is illustrated by an actual example in the supervised classification in this paper.关键词：fuzzy c-means （FCM）;possibilistic c-means （PCM）;untrained types
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发布时间：2021-06-10 - 摘要：In remote sensing, it is necessary to correct the images for distortions due to Earth shape, Earth rotation, variations in satellite orbit and satellite attitude. In this paper, we analyze the effect of attitude deviation on the transverse proportion distortion and the portrait squirm distortion of AVHRR image, and point out that the rolling of satellite can bring image transverse proportion distortion just like the Earth shape’s performance. We also develop a corresponding correction model.关键词：AVHRR image;attitude deviation;transverse proportion distortion;GCPs/GCBs
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发布时间：2021-06-10 - 摘要：A novel error compensated prediction tree method used for lossless compression of multispectral imagery is proposed in this paper. This method combines prediction tree and adaptive linear prediction techniques, so the spatial redundancy, spectral statistical redundancy and spectral structural redundancy in multispectral imagery are all exploited. For each pixel of the imagery, the prediction tree based on interband structural similarity is used to remove the spatial redundancy and a prediction error is created. Then this error is compensated by an interband linear adaptive predictor, which is constructed according to the spectral statistical redundancy. Our method removes the spectral structural and statistic redundancies as well as the spatial redundancy, so the better compression results can be obtained. The construction of adaptive predictor for each pixel will introduce prohibitive computational complexity to the algorithm. Therefore a modified algorithm based on local stability of imagery is also designed to reduce the computational complexity. The experimental results from practical multispectral images have shown that our method is better than the original prediction tree one.关键词：multispectral imagery;Lossless compression;Prediction tree;error compensation
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发布时间：2021-06-10 - 摘要：Because the statistical unit of catch production is fishing grid whose size is 30’×30’or 10’×10’ in marine fishery, the horizontal temperature gradient of fishing grid need to be calculated in order to analyze fishing ground environment by scientists. But there are the questions of real distance, irregular grid （after fishing grid is projected to Mercator projection） , value of grid points （ not cell value） if current commercial GIS software is used to calculated temperature gradients of fishing grid. For example, the max relative error of temperature gradient of fishing grid reaches 26. 48% , and the max absolute error of horizontal temperature gradient of fishing grid is 0. 124℃/10km, which is caused by the question of real distance and calculated from SST isolines on January 1-4,2001 in Northwest Pacific Ocean. A new algorithm to calculate horizontal temperature gradient of fishing grid from SST isoline is presented in this paper. The basic principle of this new algorithm is as follow: Interpolating temperature of fishing grid points in geographical coordinate system in order to build regular grid and index lines which angle is 45 degrees. The multi-section algorithm is used to interpolate temperature of fishing grid points, and exceptional temperature values are dealt with single point change surface interpolation containing orientation. The coordinate of fishing grid points with interpolating temperature is projected using Mercator projection, and the regular fishing grid becomes irregular fishing grid. The eight direction horizontal temperature gradients are computed with temperature values of nine points on each fishing grid, and the length of any two points, which is an important parameter, uses geodetic distance of elliptic earth. The methods of validating results are as follows: （1） The interpolating temperature of grid points is validated with two methods. One is manual estimation with temperature values of fishing grid points overlaying original SST isoline. Another is to compare SST isoline by overlaying original SST isoline on SST isoline generated with interpolating temperature of grid points. The same methods are used to validate the interpolating temperature of grid points by ArcGIS TIN. The result by algorithm of this paper is better than results by ArcGIS TIN. （ 2 ） The horizontal temperature gradient of fishing grid is validated by manual estimation with horizontal temperature gradient values of fishing grid overlaying original SST isoline. The same methods are used to validate results by ArcGIS GRID the interpolating temperature of grid points by ArcGIS. The result by algorithm of this paper is better than the results by ArcGIS.关键词：marine fishery GIS;horizontal temperature gradient;error analysis;fishing grid;multi-section interpolating
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发布时间：2021-06-10 - 摘要：Language as the basic communication tool is one of the most significant functions of human beings. Geospatial information is the most important component of the human recognition of reality. From verbal and text language to map and GIS which is considered as the third generation of geographic languages, the evolution of geographic languages conveys the striking impact of information technology. The intrinsic obscure metaphor based information encoding and decoding tendency in lower dimensions of space misleads the communication between information and human. The innovation of information technology drives us to research and develop a further more powerful geographic language to maximize the information bandwidth from the environment to the brain, virtual geographic environments （ VGE ） as new generation of geographic languages is thus proposed. This paper discusses the linguistic characteristics of VGE vs. GIS or map in such several aspects as（1） the multi-dimensional （including dynamic） abstract representations of the real world. （2） the multi-modal visualizations with multi-viewpoint and multi-details, and analytical understanding. （3 ） the multiple natural interactions and geocollaboration across time, space and scale. （4） the multi-sensory spatial perceptual capability. VGE provides an integrated ideographic system and the capabilities of spatial information communication to facilitate user’s perception of the geospace similar to the human’s perception in the natural world, the information bandwidth from the real world to the human brain is then maximized. The authors therefore propose that VGE is the upmost geospatial information communication tools and human-computer interface, i. e. provides the augmentation of sensory reality, or succeeds GIS as the fourth generation of geographic languages from text to map and GIS, which is opening up new ways for us to comprehend the real world.关键词：virtual geographic environments;integrated ideographic system;geographic language;user-centered
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发布时间：2021-06-10 - 摘要：Remote sensing of soil moisture by microwave radiometry has been a subject of intensive studies in the past two decades. Following the studies done before, a new approach to retrieve surface layer soil moisture is accomplished in this paper, in which the passive microwave data of TRMM/TMI and ground observation data have been used to retrieve surface soil moisture. Surface and atmosphere microwave radiance transfer models have been applied to analyze the effects of surface and atmosphere, e. g. scan angle, surface roughness, and canopy layer. In the retrieval technique for TMI low frequency, variable gain and intercept appeared. Multi-spectrum remote sensing information, surface digital elevation measurement data, and mixed-pixel information were involved. The consistency was obtained between the retrieval results and ground observation or HUBEX IOP data.
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发布时间：2021-06-10 - 摘要：Classification and pattern recognition of high dimensional remote sensing data are distinctly different from traditional multi-channel remote sensing classification techniques. In this paper, a newly integrated feature extraction algorithm based on GA and wavelet/wavelet packet （WP） transform is proposed for high dimensional data reduction and classification. The proposed algorithm combines the advantages of GA’s global optimization and wavelet’s multiresolution and multi-scale analysis. Hyperspectral signals are firstly transformed to feature domain by using a discrete wavelet or wavelet packet decomposition strategy. Since the discrete wavelet transform （DWT） is a linear transform, the DWT coefficients at specific scales could be directly used as linear features. Followed by the decomposition phase is optimal feature subset selection, in which the optimal feature subset acquired the best divergence is obtained according to interclass/intraclass distance of the training samples. This procedure is implemented by a Genetic Algorithm, with each possible feature subset encoded as chromosome. Fitness scores in GA are calculated and evaluated based on Jeffries-Matusita distance of the selected training samples. Hyperspectral data are classified with maximum likelihood classifier （ MLC）. Experimental results show that the use of DWT/WP and GA-based feature extraction technique improves the overall classification accuracy by 1. 1%-6. 5% , as compared to the use of conventional feature extraction techniques, such as principal component analysis （ PCA） , Discriminant Analysis Feature Extraction （ DAFE） and Decision Boundary Feature Extraction （ DBFE）.关键词：feature extraction;wavelet and wavelet packet;genetic algorithm
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发布时间：2021-06-10 - 摘要：Fusion of images with different spatial resolution can improve visualization of the images involved. This study tries to show that the fusion of the images from the same sensor system can also improve classification accuracy of the images. Four image fusion algorithms have been employed in the study of data fusion and classification of Landsat 7 ETM + imagery, taking southeastern part of Fuzhou City as the study area. These are the Smoothing Filter-Based Intensity Modulation （SFIM）, Modified Brovey （MB） Transform, Multiplication （MLT） Transform, and High-Pass Filter （HPF） Transform. The effectiveness of the four fusion algorithms has been evaluated based on spectral fidelity, high spatial frequency information gain, and classification accuracy. The study reveals that the SFIM transform is the best method in retaining spectral information of original image, which does not cause spectral distortion, and achieving the highest classification accuracy. MB-fused image has highest spatial frequency information gain but significantly loses spectral properties of the original image. The study shows all four fusion algorithms used can significantly improve the classification accuracy of the fused imagery. Therefore, fused images from the same sensor system can be used for improving not only visual interpretation but also classification accuracy due to free of the seasonal difference, various solar illumination and other environmental condition differences, and co-registration errors, which are common to the fusion using images from different sensor systems.关键词：remotely sensed data fusion;image classification;algorithm evaluation
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发布时间：2021-06-10 - 摘要：This paper addresses the problem of stereo image pair compression in remote sensing applications. Three fundamental techniques including Disparity Compensation （DC） , Radiation Compensation （ RC） and the compression of residual image are discussed. The main issue of stereo image compression is the estimation of disparity between the left frame and the right frame, a problem similar to the estimation of motion vectors in video coding. Since the disparity consisting in remote sensing image pairs are caused by variation in elevation rather than motion of the some objects, it is generally more universal and complex than the motion vectors. However, due to the geometrical constraint between the two frames, the vertical disparity vectors of remote sensing stereo image pairs can always be eliminated by a certain relative-orienting method. Besides stereo disparity, the average grayscale difference between corresponding blocks is also a big obstacle for creating accurate predictive image, for the two frames of a remote sensing image pair usually have considerable luminance disparity due to the changing in photograph angle and incidence angle. To fully exploit the redundancy between the two frames, a Stereo Compensation （SC） technique combining adaptive DC with RC is presented in this paper. It shows good performance in predicting the right frame from the left frame. A high-performance integer wavelet image coder is utilized for the compression of residual image. Experiments show that the SC-based compression algorithm for remote sensing stereo image pair is about 5% and 30%-45% more efficient than JPEG2000 in lossless compression and lossy compression respectively.
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发布时间：2021-06-10 - 摘要：The China land cover database with 1 km spatial resolution, a part of GLC2000 , has been developed with the 10-day composite SPOT VGT data over a period of 01 January 2000 to 31 December 2000 and the multi-spectral data of the last decade of August 2000. The multi-spectral image of the last decade of August 2000 was then used since the NDVI datasets are not sensitivie to the area with poor vegetations in northwest China. Land-cover mapping for large area will face the problem that the study area landscape greatly varies with the climate, terrain and soil, and it is a common phenomenon that the different objects have the same spectral information or the same object has different spectral information. In order to resolve this problem, the whole territory of China had been stratified into eight relative homogenous bio-climatic strata and one specific Tibet region. The stratification was carried out based on the climate condition （ above 10℃ accumulated temperature and aridity） , and then all data pre-processing, classification, interpreting and labeling processes had been carried out in each stratum, respectively. This would be good for the accuracy of the result and process of the data. In order to remove cloud contamination and interpolate the missing data masked by cloud, the Harmonic Analysis of Time Series （ HANTS） was applied to pre-process the 36 layer of VGT S10 NDVI dataset, and the ancillary metric derived from temperature, precipitation and DEM has been developed with the Analytic Hierarchy Process （ AHP） algorithm to improve the discriminating ability of VGT metrics. With the assistance of Erdas ISODATA algorithm, the classification has been carried out, and 22 types of land cover had been labeled in the whole China according to the Land Cover Classification System developed by the UN Food and Agriculture Organization （FAO） in the framework of the AFRICOVER project. The accuracy assessment was complemented by comparing with the data derived from the product with the statistic data from Chinese Statistics Bureau.关键词：China land cover;SPOT VGT;geophysical factors;HANTS
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发布时间：2021-06-10 - 摘要：A Map Matching Algorithm Based on Road Reduction Filter（RRF） is proposed in this paper, which pays particular attention to the matching problems that arise at intersections. Application of credibilist multi-criteria association using belief theory and Dempster-Shafer’s rule in only two roads map matching problem is studied. Two criteria, the shortest Euclidean distance and the smallest angle difference between road segment and vehicle heading are presented. Moreover, the correlation theory is introduced to simplified MM problems from multiread segments to only double road segments. As a result, the probability assignment function in criteria can be adjusted adaptively in accordance with actual road network. Simulation results with actual field experimental data show that RRF can perfectly solve the MM problem at urban intersections.
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发布时间：2021-06-10 - 摘要：In this paper, a new technique to the problem of road recognition in TM images is presented. The algorithm takes advantage of the characteristics of TM images. It uses steerable filters to collect candidate road objects in the images, then the chain code is used to represent these candidates and computer their parameters, and in the last step we recognize those true roads according to some knowledge and make the result more rational by post - processing. The result is satisfying considering the low resolution of the TM images. Results on the TM images of Taiwan area are given to demonstrate the efficiency of our method.关键词：TM images;steerable filter;road recognition
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发布时间：2021-06-10
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