2003年 第13卷 第1期
2003, 13(1): 2-8.
摘要:
GIS technology has been mostly concerned with handling physical data and modeling physical environment. However, the requirements of GIS for handling socio-economic information in many cases are different from those concerning phenomena in the physical environment. Analysis of capital flow among regions requires the transitions both from economic values to physical landscape and from physical surface to economic explanation. Rapid growth of Chinese economy conies mainly from investment. There are two main ways for obtaining high growth of investment. One is government expenditure which usually invests in regional facility and amenity block, which is regarded as stimulus for attracting investment. The other is the creation of investing center and corresponding capital source areas, both of which need the central city with the highest growth rate of investment among regions. This paper presents the cluster areas of both government revenue and total investment, the potential situation of capital flow between central city Shanghai and its neighbor provinces by using "Classification" and "Interpolation" functions of ArcView GIS.
GIS technology has been mostly concerned with handling physical data and modeling physical environment. However, the requirements of GIS for handling socio-economic information in many cases are different from those concerning phenomena in the physical environment. Analysis of capital flow among regions requires the transitions both from economic values to physical landscape and from physical surface to economic explanation. Rapid growth of Chinese economy conies mainly from investment. There are two main ways for obtaining high growth of investment. One is government expenditure which usually invests in regional facility and amenity block, which is regarded as stimulus for attracting investment. The other is the creation of investing center and corresponding capital source areas, both of which need the central city with the highest growth rate of investment among regions. This paper presents the cluster areas of both government revenue and total investment, the potential situation of capital flow between central city Shanghai and its neighbor provinces by using "Classification" and "Interpolation" functions of ArcView GIS.
2003, 13(1): 9-14.
摘要:
In terms of demands of rice farming in the southern China, the information processing system and the yield measurement system that is installed in combine harvester, are designed and completed. Now the systems have been used in demonstration site in the Experiment Base of Shanghai Precision Agriculture. Based on the idea of spatial-oriented, object-oriented, user-oriented, the Farm Geographic Information System for precision farming of rice was developed, which is characterized by intelligence and visualized. The Decision-making Management System is integrated with rice growth model, expert model for rice cultivation. The DGPS, RS, GIS and intelligence sensors and computer technique were adopted in building the artificial intelligence system for measuring grain yield that is installed in combine harvester, so the combine harvester could provide the grain yield distribution map real-timely. The environmental and economic assessment shows that the precision rice farming applied in the demonstration site will benefit the society, economy and ecology greatly.
In terms of demands of rice farming in the southern China, the information processing system and the yield measurement system that is installed in combine harvester, are designed and completed. Now the systems have been used in demonstration site in the Experiment Base of Shanghai Precision Agriculture. Based on the idea of spatial-oriented, object-oriented, user-oriented, the Farm Geographic Information System for precision farming of rice was developed, which is characterized by intelligence and visualized. The Decision-making Management System is integrated with rice growth model, expert model for rice cultivation. The DGPS, RS, GIS and intelligence sensors and computer technique were adopted in building the artificial intelligence system for measuring grain yield that is installed in combine harvester, so the combine harvester could provide the grain yield distribution map real-timely. The environmental and economic assessment shows that the precision rice farming applied in the demonstration site will benefit the society, economy and ecology greatly.
2003, 13(1): 15-19.
摘要:
China is a great agricultural country with large population, limited soil resources and traditional farming mode, so the central government has been attaching great importance to the development of agriculture and put forward a new agricultural technology revolution-the transformation from traditional agriculture to modern agriculture and from extensive farming to intensive farming. Digital agriculture is the core of agricultural informatization. The enforcement of digital agriculture will greatly promote agricultural technology revolution, two agricultural transformations and its rapid development, and enhance China's competitive power after the entrance of WTO. To carry out digital agriculture, the frame system of digital agriculture is required to be studied in the first place. In accordance with the theory and technology of digital earth and in combination with the agricultural reality of China, this article outlines the frame system of digital agriculture and its main content and technology support.
China is a great agricultural country with large population, limited soil resources and traditional farming mode, so the central government has been attaching great importance to the development of agriculture and put forward a new agricultural technology revolution-the transformation from traditional agriculture to modern agriculture and from extensive farming to intensive farming. Digital agriculture is the core of agricultural informatization. The enforcement of digital agriculture will greatly promote agricultural technology revolution, two agricultural transformations and its rapid development, and enhance China's competitive power after the entrance of WTO. To carry out digital agriculture, the frame system of digital agriculture is required to be studied in the first place. In accordance with the theory and technology of digital earth and in combination with the agricultural reality of China, this article outlines the frame system of digital agriculture and its main content and technology support.
2003, 13(1): 20-24.
摘要:
Precision Agriculture, also known as Precision Farming, or Prescription Farming, is a modern agriculture technology system, which brings "precision" into agriculture system. All concepts of Precision Agriculture are established on the collection and management of variable cropland information. As the tool of collecting, managing and analyzing spatial data, GIS is the key technology of integrated Precision Agriculture system. This article puts forward the concept of Farmland GIS and designs Farmland GIS into five modules, and specifies the functions of the each module, which builds the foundation for practical development of the software. The study and development of Farmland GIS will propel the spreading of Precision Agriculture technology in China.
Precision Agriculture, also known as Precision Farming, or Prescription Farming, is a modern agriculture technology system, which brings "precision" into agriculture system. All concepts of Precision Agriculture are established on the collection and management of variable cropland information. As the tool of collecting, managing and analyzing spatial data, GIS is the key technology of integrated Precision Agriculture system. This article puts forward the concept of Farmland GIS and designs Farmland GIS into five modules, and specifies the functions of the each module, which builds the foundation for practical development of the software. The study and development of Farmland GIS will propel the spreading of Precision Agriculture technology in China.
2003, 13(1): 25-29.
摘要:
This paper discusses the methods and process of Geographic Information System(GIS)applied in soil spatial analysis, involving the collection of soil spatial data that GIS required, spatial analysis method of soil nutrient, land use, slope and exposure of geography, crop yield and other factors, and also including acquiring soil spatial information and creating thematic map, and so on. Taking Hengjing Town in Wuxian County of Jiangsu Province as a case study and the maximum income as a principle, and applying the GIS methods and their interrelated models, we have calculated the most optimized agricultural land and the possible maximum income of Hengjing Town. According to the method, we can rationally regulate local agricultural production, and put forward some scenarios for optimizing agricultural structure of Hengjing Town. The paper puts forward an evaluation method of land adaptability based on soil spatial analysis, and offers some research clews to optimize agricultural land use constitution, so the paper will be have important reference value for soil study.
This paper discusses the methods and process of Geographic Information System(GIS)applied in soil spatial analysis, involving the collection of soil spatial data that GIS required, spatial analysis method of soil nutrient, land use, slope and exposure of geography, crop yield and other factors, and also including acquiring soil spatial information and creating thematic map, and so on. Taking Hengjing Town in Wuxian County of Jiangsu Province as a case study and the maximum income as a principle, and applying the GIS methods and their interrelated models, we have calculated the most optimized agricultural land and the possible maximum income of Hengjing Town. According to the method, we can rationally regulate local agricultural production, and put forward some scenarios for optimizing agricultural structure of Hengjing Town. The paper puts forward an evaluation method of land adaptability based on soil spatial analysis, and offers some research clews to optimize agricultural land use constitution, so the paper will be have important reference value for soil study.
2003, 13(1): 30-33.
摘要:
The subsiding land can be extracted from Remote Sensing image based on its spectral and spatial features. The features of subsiding land caused by mining, especially its RS information features and relative knowledge are proposed. Three methods can be used to extract subsiding land from RS image. The first is to categorize the region into different blocks(or layers)according to their features and apply corresponding strategies for each block, the second is to identify the changeable region based on GIS firstly and then to classify those regions, and the third is to post-process the classified image by traditional methods or ANN(Artificial Neural Network)methods based on domain knowledge and GIS. Two direct extraction methods are introduced also. One is the extraction based on the water accumulating property of subsiding land, and the other is based on the dynamic change of land cover in subsiding land.
The subsiding land can be extracted from Remote Sensing image based on its spectral and spatial features. The features of subsiding land caused by mining, especially its RS information features and relative knowledge are proposed. Three methods can be used to extract subsiding land from RS image. The first is to categorize the region into different blocks(or layers)according to their features and apply corresponding strategies for each block, the second is to identify the changeable region based on GIS firstly and then to classify those regions, and the third is to post-process the classified image by traditional methods or ANN(Artificial Neural Network)methods based on domain knowledge and GIS. Two direct extraction methods are introduced also. One is the extraction based on the water accumulating property of subsiding land, and the other is based on the dynamic change of land cover in subsiding land.
2003, 13(1): 34-38.
摘要:
Now GIS is turning into a good tool in handling geographical, economical, and population data, so we can obtain more and more information from these data. On the other hand, in some cases, for a calamity, such as hurricane, earthquake, flood, drought etc., or a decision-making, such as setting up a broadcasting transmitter, building a chemical plant etc., we have to evaluate the total population in the region influenced by a calamity or a project. In this paper, a method is put forward to evaluate the population in such special region. Through exploring the correlation of geographical parameters and the distribution of people in the same region by means of quantitative analysis and qualitative analysis, unit population database(1km×1km)is established. In this way, estimating the number of people in a special region is capable by adding up the population in every grid involved in this region boundary. The geographical parameters are obtained from topographic database and DEM database on the scale of 1:250 000. The fundamental geographical parameter database covering county administrative boundaries and 1km×1km grid is set up and the population database at county level is set up as well. Both geographical parameter database and unit population database are able to oiler sufficient conditions for quantitative analysis. They will have important role in the research fields of data mining(DM), Decision-making Support Systems(DSS), and regional sustainable development.
Now GIS is turning into a good tool in handling geographical, economical, and population data, so we can obtain more and more information from these data. On the other hand, in some cases, for a calamity, such as hurricane, earthquake, flood, drought etc., or a decision-making, such as setting up a broadcasting transmitter, building a chemical plant etc., we have to evaluate the total population in the region influenced by a calamity or a project. In this paper, a method is put forward to evaluate the population in such special region. Through exploring the correlation of geographical parameters and the distribution of people in the same region by means of quantitative analysis and qualitative analysis, unit population database(1km×1km)is established. In this way, estimating the number of people in a special region is capable by adding up the population in every grid involved in this region boundary. The geographical parameters are obtained from topographic database and DEM database on the scale of 1:250 000. The fundamental geographical parameter database covering county administrative boundaries and 1km×1km grid is set up and the population database at county level is set up as well. Both geographical parameter database and unit population database are able to oiler sufficient conditions for quantitative analysis. They will have important role in the research fields of data mining(DM), Decision-making Support Systems(DSS), and regional sustainable development.
2003, 13(1): 39-47.
摘要:
Urban heat environmental quality(UHEQ)is affected by the interacting of weather condition and underlying surface framework of urban area. In the last two decades, many researchers from domestic and overseas have studied many problems at the aspect of urban heat environment such as urban heat islands, urban air temperature and their relation with urban land cover, city population, air pollution etc. In the recent years, Hangzhou, acting as a center city of Zhejiang Province in China, its urbanization quantum and quantity have both changed greatly, in particular, representing as business affairs building, resident real property and all kinds of specialty market having arisen in built-up zone. Based on Landsat TM images data in 1991 and 1999, urban underlying surface temperature value and Normalized Difference Vegetation Index(NDVI)were calculated using image interpreting and supervised classification technique by remote sensing software ERDAS image 8. 4. The relation model between urban underlying surface temperature(UUST)and urban air temperature was setup according to the certain correlation pattern. Reference to the relational standard of assessing human comfort and other meteorology data of Hangzhou City in summer, the spatial distribution characteristic and the spatial variation degree of human comfort of heat environmental quality are estimated and mapped on a middle scale, that is, in six districts of Hangzhou City. Then the paper reveals the main characteristic of spatial variation from 1991 to 1999. Lastly, the change mechanism is analyzed and discussed from the viewpoint of city planning, construction and environmental protection.
Urban heat environmental quality(UHEQ)is affected by the interacting of weather condition and underlying surface framework of urban area. In the last two decades, many researchers from domestic and overseas have studied many problems at the aspect of urban heat environment such as urban heat islands, urban air temperature and their relation with urban land cover, city population, air pollution etc. In the recent years, Hangzhou, acting as a center city of Zhejiang Province in China, its urbanization quantum and quantity have both changed greatly, in particular, representing as business affairs building, resident real property and all kinds of specialty market having arisen in built-up zone. Based on Landsat TM images data in 1991 and 1999, urban underlying surface temperature value and Normalized Difference Vegetation Index(NDVI)were calculated using image interpreting and supervised classification technique by remote sensing software ERDAS image 8. 4. The relation model between urban underlying surface temperature(UUST)and urban air temperature was setup according to the certain correlation pattern. Reference to the relational standard of assessing human comfort and other meteorology data of Hangzhou City in summer, the spatial distribution characteristic and the spatial variation degree of human comfort of heat environmental quality are estimated and mapped on a middle scale, that is, in six districts of Hangzhou City. Then the paper reveals the main characteristic of spatial variation from 1991 to 1999. Lastly, the change mechanism is analyzed and discussed from the viewpoint of city planning, construction and environmental protection.
2003, 13(1): 48-55.
摘要:
From the ecological viewpoint this paper discusses the urban spatial-temporal relationship. We take regional towns and cities as a complex man-land system of urban eco-community. This complex man-land system comprises two elements of "man" and "land". Here, "man" means organization with self-determined consciousness, and "land" means the physical environment(niche)that "man" depends on. The complex man-land system has three basic components. They are individual, population and community. Therefore there are six types of spatial relationship for the complex man-land system. They are individual, population, community, man-man, land-land and man-land spatial relationships. Taking the Pearl(Zhujiang)River Delta as a case study, the authors found some evidence of the urban spatial relationship from the remote sensing data. Firstly, the concentration and diffusion of the cities spatial relationship was found in the remote sensing imagery. Most of the cities concentrate in the core area of the Pearl River Delta, but the diffusion situation is also significant. Secondly, the growth behavior and succession behavior of the urban spatial relationship was found in the remote sensing images comparison with different temporal data. Thirdly, the inheritance, break, or meeting emergency behavior was observed from the remote sensing data. Fourthly, the authors found many cases of symbiosis and competition in the remote sensing data of the Pearl River Delta. Fifthly, the autoeciousness, stranglehold and invasion behavior of the urban spatial relationship was discovered from the remote sensing data.
From the ecological viewpoint this paper discusses the urban spatial-temporal relationship. We take regional towns and cities as a complex man-land system of urban eco-community. This complex man-land system comprises two elements of "man" and "land". Here, "man" means organization with self-determined consciousness, and "land" means the physical environment(niche)that "man" depends on. The complex man-land system has three basic components. They are individual, population and community. Therefore there are six types of spatial relationship for the complex man-land system. They are individual, population, community, man-man, land-land and man-land spatial relationships. Taking the Pearl(Zhujiang)River Delta as a case study, the authors found some evidence of the urban spatial relationship from the remote sensing data. Firstly, the concentration and diffusion of the cities spatial relationship was found in the remote sensing imagery. Most of the cities concentrate in the core area of the Pearl River Delta, but the diffusion situation is also significant. Secondly, the growth behavior and succession behavior of the urban spatial relationship was found in the remote sensing images comparison with different temporal data. Thirdly, the inheritance, break, or meeting emergency behavior was observed from the remote sensing data. Fourthly, the authors found many cases of symbiosis and competition in the remote sensing data of the Pearl River Delta. Fifthly, the autoeciousness, stranglehold and invasion behavior of the urban spatial relationship was discovered from the remote sensing data.
2003, 13(1): 56-61.
摘要:
Based on an analysis of the characteristics of the Forest Resources Management Information System of each development phase, and consideration of the technical trend in Geographic Information System(GIS)in the Internet Age, this paper explores the importance and the feasibility of setting up Forest Resources Management Information System based on the WEBGIS. At the same time, based on the experience of our study, the paper explores the function, structure and method of developing the Forest Resources Management Information System based on WEBGIS. With the technology of WEBGIS, the Forest Resources Management Information System with data from Huoditang Farm was set up, which makes a great impact on forest resources management. So setting up the Forest Resources Management Information System based on WEBGIS is a trend of forest resources management. In the course of setting up this system, we must pay attention to following questions:1)unify data standard and information encoding;2)change mind.
Based on an analysis of the characteristics of the Forest Resources Management Information System of each development phase, and consideration of the technical trend in Geographic Information System(GIS)in the Internet Age, this paper explores the importance and the feasibility of setting up Forest Resources Management Information System based on the WEBGIS. At the same time, based on the experience of our study, the paper explores the function, structure and method of developing the Forest Resources Management Information System based on WEBGIS. With the technology of WEBGIS, the Forest Resources Management Information System with data from Huoditang Farm was set up, which makes a great impact on forest resources management. So setting up the Forest Resources Management Information System based on WEBGIS is a trend of forest resources management. In the course of setting up this system, we must pay attention to following questions:1)unify data standard and information encoding;2)change mind.
2003, 13(1): 62-65.
摘要:
Daily and ten-day Normalized Difference Vegetation Index(NDVI)of crops were retrieved from meteorological satellite NOAA AVHRR images. The temporal variations of the NDVI were analyzed during the whole growing season, and thus the principle of the interaction between NDVI profile and the growing status of crops was discussed. As a case in point, the relationship between integral NDVI and winter wheat yield of Henan Province in 1999 had been analyzed. By putting integral NDVI values of 60 sample counties into the winter wheat yield-integral NDVI coordination, scattering map was plotted. It demonstrated that integral NDVI had a close relation with winter wheat yield. These relation could be described with linear, cubic polynomial, and exponential regression, and the cubic polynomial regression was the best way. In general, NDVI reflects growing status of green vegetation, so crop monitoring and crop yield estimation could be realized by using remote sensing technique on the basis of time serial NDVI data together with agriculture calendars.
Daily and ten-day Normalized Difference Vegetation Index(NDVI)of crops were retrieved from meteorological satellite NOAA AVHRR images. The temporal variations of the NDVI were analyzed during the whole growing season, and thus the principle of the interaction between NDVI profile and the growing status of crops was discussed. As a case in point, the relationship between integral NDVI and winter wheat yield of Henan Province in 1999 had been analyzed. By putting integral NDVI values of 60 sample counties into the winter wheat yield-integral NDVI coordination, scattering map was plotted. It demonstrated that integral NDVI had a close relation with winter wheat yield. These relation could be described with linear, cubic polynomial, and exponential regression, and the cubic polynomial regression was the best way. In general, NDVI reflects growing status of green vegetation, so crop monitoring and crop yield estimation could be realized by using remote sensing technique on the basis of time serial NDVI data together with agriculture calendars.
2003, 13(1): 66-72.
摘要:
In this paper, based on a new Geographic Information System(GIS)grid-based three-dimensional(3D)deterministic model and taken the slope unit as the study object, the landslide hazard is mapped by the index of the 3D safety factor. Compared with the one-dimensional(1D)model of infinite slope, which is now widely used for deterministic model based landslide hazard assessment in GIS, the GIS grid-based 3D model is more acceptable and is more adaptable for three-dimensional landslide. Assuming the initial slip as the lower part of an ellipsoid, the 3D critical slip surface in the 3D slope stability analysis is obtained by means of a minimization of the 3D safety factor using the Monte Carlo random simulation. Using a hydraulic model tool for the watershed analysis in GIS, an automatic process has been developed for identifying the slope unit from digital elevation model(DEM)data. Compared with the grid-based landslide hazard mapping method, the slope unit possesses clear topographical meaning, so its results are more credible. All the calculations are implemented by a computational program, 3DSlopeGIS, in which a GIS component is used for fulfilling the GIS spatial analysis function, and all the data for the 3D slope safety factor calculation are in the form of GIS data(the vector and the grid layers). Because of all these merits of the GIS-based 3D landslide hazard mapping method, the complex algorithms and iteration procedures of the 3D problem can also be perfectly implemented.
In this paper, based on a new Geographic Information System(GIS)grid-based three-dimensional(3D)deterministic model and taken the slope unit as the study object, the landslide hazard is mapped by the index of the 3D safety factor. Compared with the one-dimensional(1D)model of infinite slope, which is now widely used for deterministic model based landslide hazard assessment in GIS, the GIS grid-based 3D model is more acceptable and is more adaptable for three-dimensional landslide. Assuming the initial slip as the lower part of an ellipsoid, the 3D critical slip surface in the 3D slope stability analysis is obtained by means of a minimization of the 3D safety factor using the Monte Carlo random simulation. Using a hydraulic model tool for the watershed analysis in GIS, an automatic process has been developed for identifying the slope unit from digital elevation model(DEM)data. Compared with the grid-based landslide hazard mapping method, the slope unit possesses clear topographical meaning, so its results are more credible. All the calculations are implemented by a computational program, 3DSlopeGIS, in which a GIS component is used for fulfilling the GIS spatial analysis function, and all the data for the 3D slope safety factor calculation are in the form of GIS data(the vector and the grid layers). Because of all these merits of the GIS-based 3D landslide hazard mapping method, the complex algorithms and iteration procedures of the 3D problem can also be perfectly implemented.
2003, 13(1): 73-78.
摘要:
In this paper a new method is developed to make a dynamic layout adjustment and navigation for enterprise Geographic Information System(GIS)based on object mark recognition. The extraction of object mark images is based on some morphological structural patterns, which are described by morphological structural points, contour property, and other geometrical data in a binary image of enterprise geographic information map. Some pre-processing methods, contour smooth following, linearization and extraction patterns of structural points, are introduced. If any special object is selected to make a decision in a GIS map, the all information around it will be obtained. That is, we need to investigate similar object enterprises around selected region to analyse whether it is necessary for establishing the object enterprise at that place. To further navigate GIS map, we need to move from one region to another. Each time a region is formed and displayed based on the user's focus. If a focus point of a map is selected, in terms of extracted object mark image, a dynamic layout and navigation diagram is constructed. When the user changes the focus(i. e. click a node in the navigation mode), a new sub-diagram is formed by dropping old nodes and adding new nodes. The prototype system provides effective interfaces that support GIS image navigation, detailed local image/map viewing, and enterprise information browsing.
In this paper a new method is developed to make a dynamic layout adjustment and navigation for enterprise Geographic Information System(GIS)based on object mark recognition. The extraction of object mark images is based on some morphological structural patterns, which are described by morphological structural points, contour property, and other geometrical data in a binary image of enterprise geographic information map. Some pre-processing methods, contour smooth following, linearization and extraction patterns of structural points, are introduced. If any special object is selected to make a decision in a GIS map, the all information around it will be obtained. That is, we need to investigate similar object enterprises around selected region to analyse whether it is necessary for establishing the object enterprise at that place. To further navigate GIS map, we need to move from one region to another. Each time a region is formed and displayed based on the user's focus. If a focus point of a map is selected, in terms of extracted object mark image, a dynamic layout and navigation diagram is constructed. When the user changes the focus(i. e. click a node in the navigation mode), a new sub-diagram is formed by dropping old nodes and adding new nodes. The prototype system provides effective interfaces that support GIS image navigation, detailed local image/map viewing, and enterprise information browsing.
2003, 13(1): 79-83.
摘要:
In order to apply Satellite Remote Sensing(RS)to mining areas, some key issues should be solved. Based on an introduction to relative studying background, related key issues are proposed and analyzed oriented to the development of RS information science and demands of mining areas. Band selection and combination optimization of Landsat TM is discussed firstly, and it proved that the combination of Band 3, Band 4 and Band 5 has the largest information amount in all three-band combination schemes by both N-dimensional entropy method and Genetic Algorithm(GA). After that the filtering of Radarsat image is discussed. Different filtering methods are experimented and compared, and adaptive methods are more efficient than others. Finally the classification of satellite RS image is studied, and some new methods including classification by improved BPNN(Back Propagation Neural Network)and classification based on GIS and knowledge are proposed.
In order to apply Satellite Remote Sensing(RS)to mining areas, some key issues should be solved. Based on an introduction to relative studying background, related key issues are proposed and analyzed oriented to the development of RS information science and demands of mining areas. Band selection and combination optimization of Landsat TM is discussed firstly, and it proved that the combination of Band 3, Band 4 and Band 5 has the largest information amount in all three-band combination schemes by both N-dimensional entropy method and Genetic Algorithm(GA). After that the filtering of Radarsat image is discussed. Different filtering methods are experimented and compared, and adaptive methods are more efficient than others. Finally the classification of satellite RS image is studied, and some new methods including classification by improved BPNN(Back Propagation Neural Network)and classification based on GIS and knowledge are proposed.
2003, 13(1): 84-90.
摘要:
Based on the analysis of the development of GIS technology and application, this paper brought forward the concept of CoGIS, namely Cooperative GIS. CoGIS is GIS facing group-users and supporting human-human interaction, which makes it differ from the former GISs. Then, the characteristics of general Computer Support Cooperative Work(CSCW)applications and the complexity of Geographic Information Science were analyzed, and the conclusion that CoGIS was not a simple GIS layer on CSCW was reached. Further, this paper gave the hierarchical architecture of CoGIS, and analyzed the cooperative platform in detail from the following:1)basic elements;2)collaboration patterns;3)cooperation control mechanism;4)synchronization mechanism;5)security and 6)group communication and so on. With those, the problems about GIS applications are discussed, such as 1)distributed multi-source GIS information and knowledge sharing platform;2)the fusion and visualization of GIS information;3)virtual reality cooperative modeling;4)dynamic simulation;5)expert system and 6)decision-making. Finally, this paper analyzed CoGIS application mode in brief.
Based on the analysis of the development of GIS technology and application, this paper brought forward the concept of CoGIS, namely Cooperative GIS. CoGIS is GIS facing group-users and supporting human-human interaction, which makes it differ from the former GISs. Then, the characteristics of general Computer Support Cooperative Work(CSCW)applications and the complexity of Geographic Information Science were analyzed, and the conclusion that CoGIS was not a simple GIS layer on CSCW was reached. Further, this paper gave the hierarchical architecture of CoGIS, and analyzed the cooperative platform in detail from the following:1)basic elements;2)collaboration patterns;3)cooperation control mechanism;4)synchronization mechanism;5)security and 6)group communication and so on. With those, the problems about GIS applications are discussed, such as 1)distributed multi-source GIS information and knowledge sharing platform;2)the fusion and visualization of GIS information;3)virtual reality cooperative modeling;4)dynamic simulation;5)expert system and 6)decision-making. Finally, this paper analyzed CoGIS application mode in brief.
2003, 13(1): 91-96.
摘要:
Several image fusion approaches for CCD/SAR images are studied and the performance evaluation of these fusion approaches is completed in this paper. Firstly, the preprocessing of CCD/SAR images before fusion is fulfilled. Then, the image fusion methods including linear superposition, nonlinear operator method and multiresolution methods, of which the multiresolution methods include Laplacian pyramid, ratio pyramid, contrast pyramid, gradient pyramid, morphological pyramid and discrete wavelet transform, are adopted to fuse two types of images. Lastly, the four performance measures, standard deviation, entropy, cross entropy and spatial frequency, are calculated to compare the fusion results by different fusion approaches in this paper. Experimental results show that contrast pyramid, morphology pyramid and discrete wavelet transformation in multiresolution approaches are more suitable for CCD/SAR image fusion than other ones proposed in this paper and the objective performance evaluation of CCD/SAR image fusion approaches are effective.
Several image fusion approaches for CCD/SAR images are studied and the performance evaluation of these fusion approaches is completed in this paper. Firstly, the preprocessing of CCD/SAR images before fusion is fulfilled. Then, the image fusion methods including linear superposition, nonlinear operator method and multiresolution methods, of which the multiresolution methods include Laplacian pyramid, ratio pyramid, contrast pyramid, gradient pyramid, morphological pyramid and discrete wavelet transform, are adopted to fuse two types of images. Lastly, the four performance measures, standard deviation, entropy, cross entropy and spatial frequency, are calculated to compare the fusion results by different fusion approaches in this paper. Experimental results show that contrast pyramid, morphology pyramid and discrete wavelet transformation in multiresolution approaches are more suitable for CCD/SAR image fusion than other ones proposed in this paper and the objective performance evaluation of CCD/SAR image fusion approaches are effective.
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