最新刊期
卷 ， 期 5 ， 2005
- 摘要：This paper discusses how to implement the procedure of information extraction from data and knowledge discovery from information in the grid computing environment, from the point of view of grid technology and information grid. Two hierarchical concepts, namely, generalized spatial information grid and special spatial information grid are proposed by the author. The former is defined as a new generation spatial information system embedded in the environment of grid technology where spatial data acquiring, updating, transferring, storing, processing, analyzing, information extracting and knowledge discovering are carried out. In order to do so, it is believed by the author that at least four functional components are needed: a smart sensor web, an intelligent data-information-knowledge processing system based on grid computing, a new generation GIS suitable to grid computing environment and Intelligent geo-service agents. The latter refers to the new generation of geographic information system in the environment of grid technology. Since conventional GISs have being developed for single person computers, four challenges caused by four types of inconsistencies are arisen when such systems are transferred to computing grid environment, they are: Challenges caused by temporal datum inconsistency, Challenges caused by geographic datum inconsistency, Challenges caused by data format inconsistency and Challenges caused by semantic inconsistency. Geospatial data representation should be re-considered if grid technology is concerned. An innovative concept, Spatial Information Multi-Grid （SIMG）, is proposed by the author and regarded as the backbone characteristics of specialized spatial information grid. The core feature of SIMG is that demarcating the studied area into different level of grids. These grids are different in size and all attribute items describing them are various and a hierarchical structure is formed where coarse grids contains several finer grids. This paper tries to put forward the definition, tasks and components of these two concepts. Some tentative approaches for solving key problems arising from them are expounded. (关键词：grid) technology;information grid;generalized spatialized information grid;specialized information grid;smart sensor web
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发布时间：2021-06-10 - 摘要：A sunlit time computation model based on the DEM data in rough terrain is developed in this paper. In order to improve the accuracy of the calculation, an earth curvature adjusting factor Q is carried out in the model based on the former researchers. In this study, 6 typical terrain areas within China were selected and their spatial distributions of sunlit time on the vernal and autumnal equinoxes, the Summer Solstice and midwinter day in two different resolutions （500m and 1km） were calculated using the developed model. The sunlit times calculated by the revised models were compared with the previous models. And the topographic and spatial-scaling effects on the sunlit time were analyzed through two aspects: the different terrain types and different spatial scales of the original DEM data. The changing rules of sunlit time according to the geomorphology and spatial scale were found out, which are very significative in applications.关键词：sunlit time;topography;DEM;spatial scaling;spatial analysis
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发布时间：2021-06-10 - 摘要：In this paper, a model is proposed to estimate the brightness temperature of vegetated surface based on ray tracing technique to account for increasing multiple scattering effects as frequencies goes higher. The vegetation layer is composed of discrete scatters such as leaf, branch and stalk. The multiple scattering inside the vegetation layer and that between the vegetation and soil surface is accounted for by Matrix Doubling. The surface emission is calculated by IEM（Integral Equation Method） algorithm. Simulation results at higher frequency show that the emission from vegetation layer is dominant, and that the vegetation has obvious extinction to surface. A good agreement is obtained by comparison of the simulation with air-bone PSR（Polarimetric Scanning Radiometer） C\|band data, and X- and Ku-band data from AMSR-E.关键词：brightness temperature;multiple scattering;integral equation method;zero-order model
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发布时间：2021-06-10 - 摘要：As human activities expanding, land use and land cover change very quickly at different scales all over the world. Remote sensing becomes a major tool to acquire information of LUCC. In recent years, the continuing development of remote sensing technology provides us a large amount of remote sensing data at high spatial, spectral and temporal resolutions. Advances in remote sensing science and diversity in high resolution data hold great promise for improving the precision of information extraction and change detection, which also make change detection of land use and land cover at different scales from global scale to local scale more difficult. However, conventional remote sensing change detection techniques are inefficient due to the high spatial heterogeneity of inner objects in the image, more texture, more details and clear edges. Moreover, the requirement for real time and effective change detection methods and large size of high spatial resolution imagery cells for development of more automatic techniques of change detection. The method of change detection based on integration of change vector analysis and similarity calibration is presented for high spatial resolution data. It can be used to detect the change of building and street quickly and automatically. In this paper, we present details of the method of change object extraction and verification The methods are illustrated with an airborne linear scanner sensor image over the suburb of Tokyo city, Japan. The result of change detection will be compatible to complexity and fuzzy degree of change of object in high spatial resolution imagery at different times, which is distinguishable to the results using conventional change detection, in which the result only provide "change" and "no-change". The experimental results suggest that change detection based on object similarity calibration is more reliable, efficient than post classification change detection using high spatial resolution imagery.关键词：high resolution imagery;change detection;similarity calibration
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发布时间：2021-06-10 - 摘要：SAR radiometric calibration accuracy is influenced by background clutter. In order to obtain high radiometric calibration accuracy, certain signal and clutter ratio （SCR） requirement must be satisfied or the SCR should be increased by clutter rejection method. This paper studies Active Coded Radiometric Calibration Technique （ACRCT） of SAR and a clutter rejection method based on azimuth signal phase shifter coding and presents the inversion of rang signal frequency modulation. We adopted Range-Doppler imaging algorithm to simulate reference point target and distributed clutter. We also studied SAR radiometric calibration accuracy by peak value method. Experiment results prove that ACRCT could effectively restrain the influence of background clutter signal and improve the precision of radiometric calibration of SAR.关键词：SAR;radiometric calibration;clutter;image formation;peak value method
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发布时间：2021-06-10 - 摘要：The special indications in Synthetic Aperture Radar images formed by oil slicks on ocean surface, which are seeped from hydrocarbon under sea bed, is important to search ocean oil and gas resources. This paper explores the segmentation of oil spills using a partial differential equation （PDE） level set method, which represents the oil slick surface as an implicit propagation interface. Specifically, the image intensity gradient is utilized as the impetus and direction for oil slick propagation. The integration of the intensity driven speed and curvature flow into the method allows the front interface to propagate naturally with topological changes, significant protrusions and narrow regions, giving rise to a stable and smooth boundary. In addition, it reduces the speckles simultaneously. The proposed method has been illustrated by experiments on oil slick segmentation using the ERS-2 SAR images. Its advantages over the traditional image segmentation approaches have also been demonstrated.关键词：image segmentation;Level Set;oil slicks;SAR
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发布时间：2021-06-10 - 摘要：Deriving thematic maps by classifying remotely sensed data was a major application fields of remote sensing techniques. The most often used classifiers in classification process of remotely sensed data include various statistical classifiers and artificial neural networks. Comparisons among these classifiers found no classifier as "panacea". While most efforts were made to develop new classifiers for more accurate classification results, to fully exploit the potentials of the existing classifiers by combining multiple existing classifiers is an effective way in many fields of pattern recognition applications. In this paper, the standard multiple classifier combination method was used for land cover mapping using remotely sensed data. Landsat TM data in Lanier Lake was used as an experimental data. Land cover maps were derived by combining classifiers at abstract level with same training features, combining classifiers at abstract level with different training features and by combining classifiers at measurement level respectively. Classification accuracies of these maps were compared with those of classifiers combined. Results showed that for all classifiers combination methods, the classification accuracies were improved. Advantages and drawbacks of every method of classifiers combination were analyzed and further study in combining multiple classifiers for remotely sensed data classification was suggested.关键词：remotely sensed data classification;multiple classifier combination;Accuracy assessment
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发布时间：2021-06-10 - 摘要：With the analysis of the status of the spaceborne Image compression, the hardware system design based on the DSP A436TM is presented for the frame and broom sensors. Compared with the special encoder, the system has the adjustable compression ration and flexible compression arithmetic program. Because of the parallel procession and prevention error code diffuseness, the scheme decreases the ration of error code effectively while improving the capability of the data procession.关键词：A436TM;image compression;lossy compression
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发布时间：2021-06-10 - 摘要：Because of the colony effect of leafs in canopy, the complex mixture of sunlit, partly shaded and fully shaded leafs causes the phenomenon that radiant temperature for dense canopy are equal to the air temperature approximately. And based on the fact, we try to retrieve the air temperature from combined reflected solar and emitted terrestrial radiation with NDVI-Ts space. The air temperature at the time of satellite passing through was estimated from the maximum and minimum air temperature measured in situ with Parton & Logan model and we still named it as "measured" air temperature. Then the results from NDVI-Ts space and P-G method were validated with "measured" air temperature. The results showed that: the air temperatures estimated from remotely sensed image with P-G model were higher and the ones from NDVI-Ts space were lower than "measured" averagely. But the remotely sensed air temperature estimated from the two methods is all with about +4℃ error compared with the "measured" air temperature. Although the NDVI-Ts space method doesn’t improve P-G model from the error scale, the NDVI-Ts space method is superior to P-G model because the former has used the remotly sensed infomation much fully than P-G model and has higher operation efficiency.
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发布时间：2021-06-10 - 摘要：Remote sensing image fusion is an effective means to realize abundant presentation of enormous image data from various origins. However in the fused remote sensing image, there may be some secrete information such as military bases that cann’t be opened to all users. Just those authorized users can completely and distinctly obtain the secrete information; partly-authorized users can only faintly see those secrete; but the unauthorized users cann’t see it. In this paper, we proposed a blind algorithm for secrete information hiding based on remote sensing image fusion and it can achieve hiding to different degrees the secrete information in the fused remote sensing image according to different popedoms of different users. Firstly, we fused the remote sensing images from various origins, chose, segmented and extracted the secrete information in the fused image and according to different users’ popedoms produced the disguised fused images by filtering and pixel complementation in which there presented the secrete information to different degrees. Then we used for reference the idea of information hiding and utilized the algorithm of odd-even embedding and JPEG standard quantization table to embed the secrete sub-image imperceptibly into the disguised fused image to produce the disguised one in which there hid secrete sub-image. While embedding, we exploited JPEG standard quantizaton table to define the quantization step which further enhanced the robustness of the algorithm against the attack of JPEG lossy compression. In addition, during the course of extracting the secrete information and resuming the fused image, this algorithm didn’t need the original remote sensing images and was a blind one. And experimental results show that this algorithm is not only quite transparent and has a good effect for large amount of secrete information hiding, but also has a strong robustness against such familiar image processes as JPEG lossy compression, noise adding, scaling, filtering, rotation and cropping. Furthermore this algorithm has no influence on various applications of the disguised fused images with the hidden secrete information to different degrees, such as edge detection and image classification.关键词：image fusion;information hiding;popedoms of users;odd-even embedding;JPEG standard quantization table
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发布时间：2021-06-10 - 摘要：It is necessary to integrate the theories and methods of commonsense geographical cognition with the data model and data organization of GIS in order to fully dig the potentials of analysis and decision-supporting of GIS in different fields. It helps to make the description and organization of geographical entity more acceptable, understandable and suitable for people’s commonsense thinking methods and habits. In this paper, the commonsense cognition activities related to data model and organization of GIS is divided into three specific parts, categorization hierarchies, entity hierarchies and the detailed descriptions of geographical entities by way of analysis of geographical cognition process. On the basis of further analysis for relevant cognition activities, we create GIS Data Meta-model to guide the conceptual modeling and computational implementation. The GIS Data Meta-model not only overcomes the attribute-based defining semantics disadvantage of traditional GIS, but also realizes the semantic representation of geographical data of different levels and the representation of semantic relationships among different data through the mapping between Categorization tree and descriptions of geographical entities. It is feasible to extract the information effectively for the application of different scale’ analysis and decision-support based on the inclusion relationship of entities between upper and lower levels and the combination relationship of same level entities.关键词：geographical cognition;data meta-model;GIS
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发布时间：2021-06-10 - 摘要：A modified normalized difference water index（MNDWI） has been proposed in this paper based on the normalized difference water index（NDWI） of Mcfeeters （1966）, which uses MIR（TM5） instead of NIR（TM4） to construct the MNDWI. The MNDWI has been tested in the ocean, lake and river areas with the background of built-up lands and/or vegetated lands, and with both clean and polluted water bodies using Landsat TM/ETM+ imagery. This reveals that the MNDWI can significantly enhance the water information, especially in the area mainly with built-up land as background. The MNDWI can depress the built-up land information effectively while highlighting water information, and accurately extract the water body information from the study areas. While the enhanced water information using the NDWI always has been mixed with built-up land noise and the area of a water body extracted based on the index is thus overestimated. Therefore, the NDWI is not suitable for enhancing and extracting water information in built-up land-dominated areas. Furthermore, the MNDWI can reveal subtle features of water more efficiently than the NDWI or other visible spectral bands do due largely to its wider dynamic data range. The application of the MNDWI in the Xiamen image has achieved an excellent result. The MNDWI image successfully reveals significant non-point pollution of the water surrounding the Xiamen Island due to agricultural activities. In addition, taking the advantage of the ratio computation, the MNDWI can remove shadow noise from water information without using sophisticated procedures, which is otherwise difficult to be removed.
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发布时间：2021-06-10 - 摘要：Three parts of property systems in hyper-spectral remote sensing data are simply expounded. The paper studies concept and method of DMN, constructs it based-on SA, and conducts segmentation of image in line with it. The researches and experiments indicate that the DMN based-on SA information may synthesize relation between spatial and spectral features existed in hyper-spectral remote sensing data; and provides control for further treatment of image such as artificial neural network. Lastly, we point out future directions of its application and research. (关键词：DMN;) hyper-spectral remote sensing;SA（spectral angle）;maximum posterior probability;spatial data mining
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发布时间：2021-06-10 - 摘要：The architecture and integration of Hyperspectral Image Processing and Analysis System（HIPAS V1.0） are introduced in this paper. Under the modularized structure, HIPAS can offer customer more extensibility and convenience on huge image data processing and information extraction. We discuss the solutions for multi-source, multi-temporal and multi-thematic data processing, analysis and products distribution. Based on the airborne remote sensing data, we extracted and realized the typical operational model of hyperspectral remote sensing applications such as classfication, mapping,index inversion, identification etc. Under the integration of key technologies and special methodologies, such as Robust Pixel Unmixing, Auto Flat Field Transformation（AFFT）, Self-Adaptive Filter（SAF）, Univeral Gravitation Classification（UGC）etc,the application modules for environment monitoring in HIPAS were also introduced in this paper. As an example, some useful and valuable applications on pollution monitoring of water resource were given together with some constructive suggestions.关键词：hyperspectral remote sensing;environment monitoring;system integration
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发布时间：2021-06-10 - 摘要：Always there are two kinds of viewpoints in the research of distribution of the Wu’s capital in spring and autumn period: The historiography circle thinks that king Wu Helu’s capital is now in Suzhou, and its understanding stems from "THE BIOGRAPHY OF PLACE WU" that was written by Lu Guangwei of Tang Dynasty. But the archaeological circle thinks that the capital positions of several generations Wu Wang from Shoumeng to Helu are migrated, they mainly lie in the Mudu basin of the west of Suzhou and its understanding stems from "YUEJUE BOOK" and "SPRING AND AUTUMN SUCH AS WU YUE" which were written in Han Dynasty, and from fragmentary archaeological unearthing. Considering the historical and geographical condition for selecting sites of the capital in the Spring and Autumn Periods synthetically,we agree with the view of the archaeological circle. In this paper, geographical investigation and analysis were made in a large area of Suzhou and Tai Hu. And on the base of further researched historical data and forefathers’ working achievement, the Wu’s capital trace position in the Spring and Autumn is investigated and predicted by means of remote sensing. It will offer reference for the fact that the archaeological circle ascertains and excavates in a planned way.
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发布时间：2021-06-10 - 摘要：According to the interpretation marks of active faults,about 200 faults were interpreted,which strike northwest, northeast, south-north and east-west respectively. Northwest-trending faults have the largest scale and regional feature, controlling the development of landforms and water systems in the Project Area. Among them, 22 faults have relatively larger effects on water transfer project. Through the field observation, it has been shown that there are 5 active faults in Holecene and 12 huge active faults in later Quaternary. However, it has been discovered by synthetical analyses that these active faults don’t have critical threat on the water transfer project because of long distance from the water transfer project or not passing through it or other factors. In summary, the water transfer project will be stable relatively through active faults analysis.关键词：active faults;remote sensing interpretation;project stability
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发布时间：2021-06-10
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