最新刊期
卷 ， 期 2 ， 2000
- 摘要：This paper introduces the operational principle of Spaceborne Synthetic Aperture Radar （SSAR）. The System Design Project of SSAR is discussed here in detail. The most important factors in the design are related with the selection of Pulse Repeating Frequency （PRF）, Doppler bandwidth, transmit and nadir interference restriction, range and azimuth ambiguity, ground swath, data transfer rate etc. Because SSAR generates a large volume of data, we can’t process these data with ordinary computer. DAWN 1000 Parallel Processing System is introduced and utilized to simulate the SSAR system. Finally, the simulation result is given, which proves the correctness of the SSAR System Design Project.关键词：spaceborne synthetic aperture radar;system design;pulse repeating frequency;ambiguity;parallel processing
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发布时间：2021-06-10 - 摘要：A novel genetic algorithm is developed for multi parameter retrieval of land surface roughness and soil moisture. The theoretical model of two scale rough surface is employed for computation of the cost function. Retrieved results by this genetic algorithm are well compared with ground truth data. This study presents a new example of the genetic algorithm for multi parameter retrieval in remote sensing.关键词：genetic algorithm;roughness and wetness;Retrieval
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发布时间：2021-06-10 - 摘要：The High Resolution Imaging Spectrometer （HIRIS） produces tremendous amounts of raw data. Transmission of these data to a ground receiving station is constrained by downlink communication bandwidth. To alleviate limitation, the data must be compressed. In this paper, we present a compression algorithm for hyperspectral image by using, three dimensional discrete cosine transform coding （3 D DCT）. The 3 D DCT includes a 1 D DCT on spectral direction followed by 2 D DCT on the eigen images produced by 1 D DCT. The main effect of the 1 D DCT is to remove the data correlation on the spectral direction, and produces the spectral band corresponded eigen images which are consisted by the DCT coefficients. The resulting spectrally decorrelated eigen images are then compressed using the JPEG algorithm. The compression ratio is controlled by the quantization （Q table） of JPEG. Image edge features are of great significance to the application of hyperspectral image. During the compression, it is pursued to retain the imgae edge feature. We have designed a Q table for retaining the edge feature with maxmum compression.关键词：hyperspectral images;transform code;JPEG;quantization;image edge feature
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发布时间：2021-06-10 - 摘要：For the multispectral image （MSI） data, there are two types of redundancy: spatial redundancy and spectral redundancy. In this paper, we classified the spectral redundancy into two categories: spectral statistical redundancy and spectral structural redundancy. The former is based on the spectral resolution. The higher spectral resolution the more redundancy. The latter is caused by the same imaging objects of all bands images, it is essentially based on the arrangement of earth objects. Essentially, the two types of redundancy are different. Here, we proposed a lossy compression technique based on wavelet transformation: Share Significance Map Wavelet Transform （SSMWT）. With this technique, zerotree coding was used in compression of MSI, and we only need to create one significance map for all bands of images in MSI, is the light of structure correlation between all bands of images after WT, and then to remove spatial correlation and spectral structure correlation. Combined with K L transformation, the spectral statistic correlation of MSI can be removed. The experiments have shown the efficiency of this technique.关键词：wavelet transform;lossy compression;share significance map
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发布时间：2021-06-10 - 摘要：The principle and method of evidential reasoning are described in the paper, which is used for combining the information from multiple data sources so that various information can be fused in remote sensing image analysis. What is most important in the method is that the uncertainty in data sources can be propagated in the process of data analysis, and the expert knowledge can also be used in the method. At the end, it is demonstrated that evidential reasoning has extensive applications in the classification of remote sensing images through the fusion analysis of ERS SAR and TM image.关键词：evidential theory;remote sensing image classification;data fusion
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发布时间：2021-06-10 - 摘要：In recent years, microwave radiometry has been developed as a powerful technique for remote Sensing of Sea ice in China. Since 1986 the thermal emission from sea ice in Liaodong Bay and Bohai Bay has been measured by multi frequency microwave radiometers designed by Changchun Institute of Geography, Academia Sinica. The paper analysizes the microwave measurement principle of sea ice thickness, introduces the model of theory about its measurement and provides the calculation formulation for sea ice radiation constant as well as the process of microwave radiometer data. The relationship between brightness temperature and sea ice thickness, salinity, temperature, frequency, polarization, etc, has been experimentally obtained. In the end, it introduces the Computer automatical process system of measurement of sea ice thickness, compares the result of theoretical calculation with the ones of practical measurement, and almost obtains the same result.关键词：microwave remote sensing;measurement of sea ice thickness;applied research
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发布时间：2021-06-10 - 摘要：The contradictions for sustainable development of Dalian gulf are dynamic. These contradictions involve spatial factors （e.g. the concentration distribution of pollutants and environmental function division, etc.）. In order to deal with and simulate contradictory mechanisms of various developing plans （various economic increase plans and urbanization plans） of the area along Dalian gulf, this paper puts forward a new conceptual GISSD frame in order to simulate the water pollutioncontrolling system of Dalian gulf. The model of the system is built. The water pollution of Dalian gulf is modeled temporally and spatially, and regulating strategies are worked out. This paper simulates the impacts on environmental quality of Dalian gulf by various development plans of the area. The combination of SD （Dynamic Modelling） and GIS （Spatial Modelling） are mutually complementary. This may describe, analyze and stimulate a complex system （e.g. complex structure, timely dynamics, and spatial factors, etc.）, and contribute to solve complex system problems. This helps decisionmaker consider dynamic contradictions of environment and development in two dimensions.关键词：dalian gulf;water pollution;geographic information system （GIS）;system dynamics （SD）;spatiotemporal modelling;regulating strategies
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发布时间：2021-06-10 - 摘要：This paper presents the mechanism research on predicting the biochemical concentration of fresh leaves by high spectral remote sensing. Based on analyzing the concentrations of seven chemical components, including total chlorophyll, water, crude protein, soluble sugar, N, P and K, with certain chemical methods and detecting their optical properties with surface spectrometre, we establish the statistical relationships between the concentration and reflectance through the stepwise multiple regression method. So did the relationships between the concentrations and several transformations of reflectance such as the reciprocal, the logarithm, and the first derivative of the reflectance. The results show good prediction performance for chlorophyll, water, crude protein, N and K with high values of the squared multiple correlation coefficients （ R 2） and high confidence level （>95%）. Especially, R 2 value of the corralation between crude protein concentration and the first derivative of reflectance is 0.9564, which is the best result in the study of the fresh leaf’s biochemistry. The research lays a good basis for further discussion on predicting leaf biochemical concentration by high spectral remote sensing in China.
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发布时间：2021-06-10 - 摘要：This paper briefly discusses the polarizing reflectance characteristics of the simple leaves of several plants. We use the self\|made photometer with A band （630\690nm） and B band （760\1100nm） to measure the polarizing reflectance at various viewing angles, incidence angles and azimuth angles. According to the analysis, the reflectance characteristics are related to both plant species sun incidence angle and sensor’s viewing geometry. In short, the corresponding study on polarizing reflectance not only help to plant recognition but also provide the theoretical basis for further researches on the remote sensing of polarized light.关键词：natural light;polarized light;polarizing reflectance
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发布时间：2021-06-10 - 摘要：On the basis of the results of studying the land resources, the land potential resources of China were analyzed and evaluated with Geographic Information System （GIS） technology and Analytic Hierarchy Process （AHP） method. The quantity and distribution characteristics of farmland potential, land productivity potential, land productivity gross potential, land people capacity potential and land comprehensive potential were then analyzed and studied. The conclusions are that the land potential resources in China is tremendous, but the distribution of these potential resources is unbalanced. Therefore, in the development and use of potential land resources, different strategies and policies should be used in difference places. On the basis of protecting and scientifically using the current land resources, the exploitation and utilization of potential land resources in the future should be conducted with the viewpoints of sustainable development.关键词：land potential resources;comprehensive evaluated;AHP
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发布时间：2021-06-10 - 摘要：Based on the main eco environmental problems in the region of Longyangxia reservoir, we designed the structure, function and database of eco environmental information system using the methods of remote sensing integrated with GIS. At the end, the environmental detection information system in the region of Longyangxia reservoir was established. The system comprises of three subsystems: the remote sensed data processing system, the eco environmental information system and the statistics database management system. This system has multifunctions with detailed spatial and attribute database including fundamental geographic elements, eco environment, landform, remotely sensed image, statistics and landscape photo data. With it a new method for extracting environmental information from remotely sensed data is applied efficiently. The eco environment was then detected dynamically. The results show as follows:\;（1） The sand desertification land has been increased in nearly one decade and kept stable development situation;\;（2） The regions of very severe and severe water erosion are mainly distributed around the Longyangxia reservoir, which not only influences on the regional eco environment but also endangers the security of the Longyangxia reservoir;\;（3） Because the structure of land use is unitary and unreasonable, the grassland is degraded seriously, which results in the expending of desertification and the decreasing of land productivity.\;The system and the research methods could be applied to the other similar areas.关键词：environment dynamical detection;remote sensing;GIS;Longyangxia reservoir
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发布时间：2021-06-10 - 摘要：It is necessary to evaluate the flooded house, population, and property as well as the economic loss. The distribution of house, population, and property are correlated with the distribution of residential areas. Their distributions can be derived from the distribution of residential areas. Therefore, it is very important to quickly obtain the residential area in flood disaster evaluation. Satellite remote sensing provide cheap data resources for delineating residential area. In this paper, the method of extracting residential area from remote sensing data is discussed. FIrstly, the mechanism of remote sensing for residential areas is analyzed. Secondly, the differences of residental area and other landuse type are discussed, and the method of enhancing the differences is explored. Thirdly, the structure feature among spectrum of residental area and the other landuse types is analyzed. The unique feature which can distinguish residental area from the other landuse types is that the TM2, TM4 and TM7 of residental area is very close, especially for residental area mainly consisted of house with cement or tile roof. It can be represented with the formula such as TM2 TM4<T1; TM4 TM7<T2; TM7 TM2<T3. When T1, T2 and T3 are given with suitable value, the residental area can be extracted with the formula. With the example of the center part of Fuqing city in Fujian province, when T1, T2 and T3 are given respectively with 10, 8 and 5, the residential area can be extracted with the position accuracy 82% and the area accuracy 80%. Some green land of residental area is not extracted from remote sensing data, which is benefit to the evaluation of flood disaster evaluation. In conclusion, the residential area can be extracted from Landsat TM with the simple threshold of spectrum structure.关键词：satellite remote sensing;residential area;spectrum structure
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发布时间：2021-06-10 - 摘要：In the Spatial Decision Support tool System （ISAT）, rules of expert system are expanded so that the expert system can not only use data extracted from GIS and database, but also need decision support models. By using these broad sense rules, we can bring knowledge process in geographic analysis, and integrate GIS, database and spatial analysis model. Model Data Blackboard is the key of integration, which consists of a variable table, a model table a true value maintaining system and a blackboard monitor. By this approach we can incorporate mathe models one by one. The system is also based on fuzzy logic. Model Data Blackboard can manage precision data and fuzzy data, and the mathe model functions exchange data between them through the model data blackboard. By prescribing the principle about computing certainty factors, certainty is processed approximately.\;Throught its knowledge macro language, the ISAT can setup a working environment for one spatial decision support course. The knowledge macro language program sets the objective of reasoning machine of the expert system, manages the input and output of the ISAT data. ISAT can interact with raster file of geographic information system, database and text file with its knowledge macro language program.\;The method introduced in this paper is also a preliminary way to design the knowledge based spatial analysis information system. We have done a case study with knowledge based investment assessment information system for urban district of Chongqing City in Sichuan province of China.关键词：Geographic information system;expert system;Model;Integration
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发布时间：2021-06-10 - 摘要：As the combination of Data Warehouse and GIS, Spatial Data Warehouse is a large database designed to support the needs of decision making. For this purpose, it has some new features that are different from those of the traditional database, such as integrated, subject oriented, time and spatial variant. The emergence of Spatial Data Warehouse extends the scope of the applications of GIS and supports the research on global change, development of region and complex analysis of commerce. The system of Spatial Data Warehouse mainly includes four components. These are data source, tools of data transformation, warehouse, and analytical tools. All of these components involve some new and key technologies. We must find answers about how to define an efficient spatial data structure, integrate various data source, and find information from raw data. They are critical to the success of building spatial data warehouse.\;From emergence system architecture to building an application of Spatial Data Warehouse, this article discusses this very new GIS application.关键词：data warehouse;GIS;spatial data warehouse
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发布时间：2021-06-10 - 摘要：National Spatial Information Infrastructure （NSII） includes principle, standards, architecture, policies and people which build and maintain a sharing geospatial information framework. Architecture is a logical model for NSII. From different dimensions we can derive five views from architecture: operational architecture, technical architecture, data architecture, system architecture and institutional architecture. The purpose of the NSII is spatial information framework.关键词：NSII;geospatial framework;NSII architecture
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发布时间：2021-06-10
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