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  • 2004 Volume 6 Issue 3
    Published: 25 September 2004
      
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  • ARTICLES
    An Examination of Early Ancient China's Ancestors Migration to America
    LIU Shuren
    2004, 6(3): 4-6.
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    The so-called“floating bridge island”,just as the American Indians referred to in 1910,is seated intoday's Bering Strait.The narrowest part was only 86km wide,and 30 to 50m deep.There were two small is-lands in the middle.Moreover,people could see each other after rain on sunny days.China's ancestors migrationto America on foot at this period of time is related to ancient sea level change,i.e.,the constant continentalglacier thawing and sea level rise in later Quaternary.Sea level is 100m lower than today's about 14000 yearsago,the Alaska continental bridge lying in the Bering Strait did exist between Asia and America;when sea levelrose to 60m about 12000 years ago,the last ice age was over,the bridge still existed;until 9000 years ago,sea level rose to negative 25m,the bridge began to be submerged,and yet water was shallow,people could stillgo through on ice in winter easily;till about 7000 years ago,it is on the eve of human civilization,sea levelwas still 5 to 6m lower than the present,people could reach America by raft or canoe,and therefore lots of Chi-nese ancestors reached America since then,records have been found in China's ancient books.As a result,China is not only a landmass country,but rather a great navigation country long before.
  • ARTICLES
    Case-Based Reasoning for Geo-Feature Indexing and Analyzing of Typical Landing Operation
    LAN Rongqin, YANG Xiaomei, Zhengzhou
    2004, 6(3): 7-11.
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    Based on cognitive psychologic process,Case-Based Reasoning(CBR)is a new method for machineself-learning and solving problem.CBR has been widely applied in many study fields served as an alternativeapproach to rulebased reasoning for solving some complex problems.Especially it has become an importantreasoning technique for intelligent decision support system.In the field of battlefield geographic environment analysis,historical landing operation geographicenvironment is very helpful to current decision-maker.By applying CBR,they can be treated as typical casesand manipulated with an example battle base.In this paper,the important value of geo-feature indexing andanalyzing of typical landing operation is reviewed.The geo-features related to landing operation are explored indetail and then classified with concept hierarchy.The techniques of CBR are applied to the design of geo-feature indexing and analyzing system of typical landing operation.They are discussed from three aspects.The first is Case Base Construction.In our system,a typical landing operation case is formally representedas the following form:Case=(problem,constrained condition,solution),which is the main body consisting ofentities and attributes of the problem.Constrained condition means the domain expert knowledge or rulerequired for constructing cases.The second is Case Indexing.When finding a solution for a new problem,CBRuses similar knowledge and feature indexing to search the most similar case to current problem from case base.This includes three sub-processes:characteristic discrimination,similarity computation,and test and evaluationwith domain expert knowledge,in which similarity computation is most important.Generally,the similarity ofthe case can be divided into four levels,that is,attribute similarity,entity similarity,level similarity,and totalsimilarity,there are many algorithms and equations for these similarity computations.The third is Selecting Indexing Strategy.There are three major case indexing strategies for CBR:NearestNeighbor(KNN),Inductive Indexing and Knowledge Guiding.In our system,since the organization andexpression of the case are based on KNN,the indexing strategy is called weighted indexing based on KNN.Finally,based on the framework of CBR and its key techniques,a case base of typical landing operationshas been built using programming language VB and VC as well as the database management system SQL Serverand Microsoft Access.It has been proved a high performance.
  • ARTICLES
    Spatial Characteristic and its Change of Urban System in China
    YANG Guoan, Gan Guohui
    2004, 6(3): 12-18.
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    The spatial pattern of urban system is the result of the location selection mainly through the economicactivities and the population migration in history.Analyzed by some quantitative methods,such as density con-trast,nearest distance comparison and the spatial autocorrelation of city distribution,this paper finds out that thecity density becomes increasingly high,however,the difference between the three economic belts still exists andthe gap of urban development between them becomes wider and wider,though the spatial contact enhanced be-tween 1985 and 2001.The calculation based on the Moran's I statistics which is a global measurement of spa-tial dependence increased during this period of time indicates that the cities distribution displays a high degreeof spatial autocorrelation in the same period.By drawing Moran's scatterplot based on city distribution in China,this paper obtains a more disaggregated view of the nature of the spatial autocorrelation for the initial and termi-nal years,and by contrast,city distribution and its spatial lag can be displayed apparently.The information en-tropy value implicates there is an equilibrium development trend in China, which is an indication of rapid de-velopment of cities and towns in the period of concerned.
  • ARTICLES
    Study on Land Data Checking Methods Based on Metadata and Data Rules
    FANG Li, LIU Shengquan, ZHONG Ershun
    2004, 6(3): 19-23.
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    Land data are basis of land information system.It is a key and necessary step for developing a landinformation system through preparing,checking and correcting land data so as to make it fit into the system.Nowadays,land management offices,information centers or other institutes of many cities and provinces havebuilt several versions of land data sets.These data sets are of multi-scale,variant sources,different requests inland data precision,and are most important.The processes of data checking to make them work properly in landinformation systems are nonstandard to be reusable.Facing to the problems of how to standardize and control theprecision of land data coming from variant sources,and how to find a reusable and more effective data pro-cessing method to lessen the manual work of GIS data checking,in this paper,usual types of land data errorsare analyzed,and based on it,a general method of land data checking will be discussed which introducesmetadata and logic rules into the system.This method is confirmed to be an effective solution in land databasehandling while used in building spatial databases of Jilin Cadastral Information System.
  • ARTICLES
    Research on the Agricultural Land Grading Information Roboticized System Using the Coefficient Revising Method Based on Expert Knowledge
    JIA Zelu, Liu Yaolin
    2004, 6(3): 24-28.
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    Agricultural land grading is still in the experimental stage and its technical routes and methods arestill discussed up to date.And there are no full-blown and self-contained agricultural land grading system atthe present time.It is very important to set up an agricultural land grading system to make grading systematiza-tion and automatization.In accordance with this situation,the author explains the necessity and feasibility ofsetting up an intelligentized and roboticized system.Agricultural land grading information system which inte-grates GIS and ES,and then based on the principles of grading,classifying and pricing agricultural land andcomposite type geographic information system(COMGIS)and computer technology,the prototype of general in-formation system of grading,classifying and pricing cropland is developed.Studies on the grading informationsystem was made using the coefficient revising method of agricultural land,based on VC++6.0 and ActiveX ofMO 2.0.This system is suitable for evaluating cropland under Chinese conditions.The modules included areprojects managing,classifying,grading,pricing,layer managing,system tools,view managing,production putout,consultation,windows and help etc.It has powerful functions in managing attributive data sets and spatial datasets,grading,classifying and pricing cropland and outputting achievements etc.,the storage of related data andtheir retrieval and statistical analysis.Various data and picture files concerning agricultural land can be provid-ed at user's request.Its interface is friendly,and the operation of the system is simple and convenient.It canrealize automatic grading,classifying and pricing agricultural land,and offer the friendly and convenient com-puter business management tool for land and government administrative department of different levels.
  • ARTICLES
    The Studies on Architecture of Spatial Logistics Information Platform Based Applet-CORBA
    LIU Mingzhu, HU Liqin
    2004, 6(3): 29-33.
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    The technology of logistic management is fastly developing enhanced by modern science and technol-ogy.The information flow is more important than ever before among logistic flow,business flow,capatial flowand information flow.The key of successful logistic management depends on the precision and real time.In thearticle,the author firstly introduced the logistic management technology,spatial information technology and theintegration of the two technologies mentioned above,and then introduced the basic architecture of CORBA andits advantages in computing distributed objects.Applet,one of java applications running in web browser,is suit-able for the characteristics of comprehensive operation of logistic management system.The architecture of spa-tial logistic platform was designed based on Applet-CORBA.The author finally analyzed the graphic user inter-face tier,business logical tier and enterprise information system tier respectively.
  • ARTICLES
    The Development of Web Data Edit Engine Based on B/S
    WANG Hanbo, T. K. Yu
    2004, 6(3): 34-37.
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    GIS Web services have the potential to revolutionize the way in which GIS is developed,accessed andused.They make it easier to share geographic data and functionality,and for GIS to be deeply integrated intoother technologies.Ordinarily,GIS Web services are used to complete display,analysis functions on the Web.Inthis paper,a framework“Easyway Suite”is presented to provide a new technology for exploring the GIS Webservices.Easyway Suite expands WebGIS applications from simple query and analysis,to advanced data collec-tion,edits,and maintenance,and helps customer build their cost-effective,distributed WebGIS network editingsystem.Easyway Suite is in S/C architecture.The Server is a Pure-Java,and platform independent Data EditingEngine,integrating with ArcSDE and Oracle.For Client-end,it provides customer with three versions of userinterface:Easyway Editor(Light),Easyway Editor(SVG),and Easyway Editor(JAVA).Based on the development ofEasyway Suite,a web data edit engine,this paper analyzes the advantage and disadvantage of current WebGISapplication,and discusses the technology,requirement,and applications of web data edit engine to explore thescope of WebGIS application.
  • ARTICLES
    On Metadata Management System of Spatial Information Based on Oracle
    WANG Jingqun, ZHAN Chesheng, LIU Baolin, LIU Xiangchao
    2004, 6(3): 38-42.
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    With the development of GIS and with the improved apparatus,spatial data are used more and morewidely in many fields.The extraordinary feature of spatial data is its plenty of information.So it is necessary tofigure a quick and effective way to manage the metadata of spatial data.Spatial metadata includes the content,quality,identifier,coordinate system,and format of spatial data.It somewhat is regarded as the index of spatialdatasets.According to the Metadata Standards of NFGIS(National Fundamental of GIS)drafted by NationalCenter of GIS,this paper discusses how to manage metadata of spatial information and build Oracle Database.Taking Ningbo GIS as an example,the building flow and architecture of spatial metadata management systemwas introduced.The study showed that spatial metadata management system can help to manage metadata morequickly' and efficiently,thus meeting the social requirement for spatial geographical data to the fullest extent.
  • ARTICLES
    The Establishment of Database for Cadastral Information System Based on GIS
    QIU Dongwei, YANG Songlin
    2004, 6(3): 43-45,50.
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    In combination with the project of establishing cadastral information system database for Land Re-sources Bureau of Haiyan County,Jiaxing of Zhejiang Province,the paper discusses the importance and urgencyof the database,puts forward the fundamental requirements according to the construction,the running,the usingand the maintenance of the database.In the form of flow chart,the paper briefly introduces a sort of method toset up the cadastral information system database.Moreover,some key technical points such as the method of da-ta acquisition,hierarchical classification and encode of cadastral data,the design scheme of the database struc-ture are discussed in detail.The paper also researches some methods to resolve a series of problems in the pro-cess of development stage of the project,and summarizes the practical experience of project development aswell.
  • ARTICLES
    Establishment of the Urgent Epidemic Situation Geographical Information System:Taking SARS Epidemic Situation's Information System as an Example
    LIU Yunyun, HU Wenliang
    2004, 6(3): 46-50.
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    Most of China was unexpectedly attacked by SARS.In the process of oppugnning SARS,facing theoperation of the mass information about epidemic situation and SARS's distributing spatiality,to adopt SARS'sepidemic information system can help people better in monitoring,preventing and curing and early warming.Onthe other hand it is imperative to build the epidemic situation geographical information system.This article,inlight of the actual data of epidemic situation and the practise of system founding,summarizes the problem andexperience which met in the process of designing and founding.It briefly discusses the establishment of the epi-demic situation geographical information system by taking SARS's information system as an example.It also dis-cusses the characteristics of SARS's information system,the principle of design,the composition of the systemand the process of system ultimately establishment.
  • ARTICLES
    The Establishment and Application of Nanji Islands Marine Natural Reserves Information System
    ZHANG Huaguo, ZHOU Changbao, HUANG Weigen, TENG Junhua, LI Dongling, XIAO Qingmei
    2004, 6(3): 51-56.
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    This paper describes the Nanji Islands Marine Natural Reserves Information System(NMNRIS)ofChina.The system is developed specially for Nanji Islands using RS,GIS and Database techniques.In NMNRIS,spatial database,remote sensing information database,shellfish and alga database and so on are established,andthe system has the functions of managing,updating and querying.In the paper,four sections are included as fol-lowing.(1)The first section describes the framework of the system,which is designed based on the analysis of theusers and their requirements.The system includes two sub-systems of spatial data and property data respective-ly.(2)In the second section,the data of the system are introduced.There are seven sub-databases in the sys-tem such as geo-database,remote sensing database,shellfish and alga database,document database,multimediadatabase and so on.(3)The functions of the system are discussed in detail from two aspects in the third section.The first func-tion is to manage spatial data and to do spatial analysis,and the other one is to manage property data.(4)Finally,the land covers analysis based on the system is discussed as an application of NMNRIS.Theresults obtained from the present investigation are as follows:(a)The main land cover types in the Nanji Islandare meadow,shrubbery,farmland,village,water body and sands.Meadow and shrubbery are the dominant types,being 89.6% of the island's total area.(b)The patch number,fractal dimension of the patch and patch perimeterare related to patch areas.The patch number decreases with the increase of the patch area whereas the fractaldimension increases with the increase of the patch area.The patch perimeter has the linear relation with thepatch area.(c)The fractal dimensions of the meadow,shrubbery,farmland and village calculated by the perime-ter-area method are 1.3433,1.3728,1.2563 and 1.2156 respectively.On the other hand,the fractal dimensionsof the meadow,shrubbery,farmland,village,water body and sands computed by the measure-perimeter-areamethod are 1.096,1.102,1.05,1.062,1.002 and 1.047 respectively.Thus,it is concluded that the meadow andshrubbery have higher dimensions compared with those of the farmland and village.It is indicated that patchstructures of the meadow and shrubbery are more complex than those of the farmland and village.Studies alsoshow that the fractal characteristics of land covers are related to the human activities.(d)The test of significanceof fractal characteristics shows that the differences between the meadow and shrubbery and the farmland andvillage are significant whereas the difference between the meadow and shrubbery and the difference betweenfarmland and village are insignificant.In a word,NMNRIS will improve the management level of the Nanji Islands Marine Natural Reserves.Atthe same time,the experiences and techniques of the project will lead the way for other similar projects,afterall,NMNRIS is the first application of RS,GIS and database techniques for Marine Natural Reserves.
  • ARTICLES
    A Preliminary Study of Public Participation GIS for Community Construction and Management——Idea and Design
    LIU Miaolong, ZHOU Lin
    2004, 6(3): 57-61,67.
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    Public participation is a basic purpose of development of GIS research and application.Design anddevelopment application of public participation GIS is a new developing field of research on geographic informa-tion system and geographic information science.Based on the practice of the daily affairs of construction andmanagement in town community and the experience and application of management information system in com-munities' affairs,from the beginning of the ideas and intensions of the public participation,this paper discussessome possible fields of the public participation,suggests a few useful participating ways,analyses the informa-tion bases,model components,system structures and framework of a public participation GIS,as well introducesa design of a PPGIS,especially about the key interfaces,applicable programs and databases in a PPGIS.By in-troducing a simple prototype of PPGIS in detail,the paper analyses the existing problems and further develop-ment of public participation geographic information system.Besides some technical problems need to be solved,an important problem is how to attract and assist residents in the community to use a PPGIS successfully intheir affairs.
  • ARTICLES
    Study on the Geographical Positioning Method Based on IEEE802.11 Wireless LANs
    SUN Rujiang, LU Guonian, YE Chun, JIAO Jie
    2004, 6(3): 62-67.
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    The paper analyses several geographical positioning methods,and sum up characters of the methodsin different scales and procedures.From IEEE802.11 Wireless LANs protocol,a new geographical positioningmethod and its procedure is presented,and the tendency of the geographical positioning method with WirelessLANs protocol in the future is discussed in the paper.Its principle is like a lighthouse which at the seasidesends signals for navigating ships to share.Precision of positioning depends on the clarity of observation.Whena AP(Access Point)in broadcast mode sends a frame that includes local MAC address,MS(Mobile Station)canreceive the signal.By the MAC address it gets its place name,geographical code,longitude and latitude,whichinclude local information.It can be positioned not only by the head of MAC frame but also by the body of MACframe.The former needs calculating of inquire,and the latter does not,so it may be suitable for this kind of mo-bile station,which likes mobile phone.The smaller the range to be receivable for the wireless signal,the higherthe positioning precision.A broadcast frame is so short,for instance,shorter than a microsecond that the AP hasfunctions of communication and positioning.Using the IEEE802.11 MAC frame to position,this method protectsthe safety of national geographical information,because it sends relative position coordinate,and hides the abso-lute position coordinate.The function of positioning can be added to Wireless LAN in existence,thus its con-struction cost is cut down greatly.
  • ARTICLES
    Simple Analysis of Building “Digital Dongying”LAN Project
    ZHAO Jun, ZHAO Tengyun, WANG Zhian, LI Shiyong
    2004, 6(3): 67-71.
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    The developing trend of the human society is economic globalization and informationization in the 21st century.Dongying firmly catches the historical opportunity brought about in the time of information revolutionwhen the informationinzation develops,fully utilizes the existing foundation and advantage,and promotes the de-velopment of the economy of Dongying.It is a magnificent project to build digital Dongying based on the presentand link to the future.There are two main tasks in digital Dongying project:Firstly,based on optic fibre of the whole city the uni-fied computer network of broadband is set up and is utilized as the basic communication network platform,andthen the connection of terminal user's broadband is realized.Secondly,pay special attention to the effort of taking government informationization as the guide,relying mainly on enterprise informationization and the base ofthe social information,the informative applications for the entire people are popularized in an all-round way,theinformation-based system is perfected to realize the whole digitization,and digital Dongying comes into being.Project of digital Dongying comprises information platform of network and basic data platform.According tothe demand and requests of digital city building,the project of “digital Dongying” LAN started operating first,and has been run in an all-sided way,the result is very good.Now the plan of infrastructure of digital Dongying,the overall plan of the network and relevant problem are analyzed and studied.
  • ARTICLES
    Feature-based Object Oriented Geographical Network Modeling
    LU Feng, SHEN Paiwei, ZHANG Mingbo
    2004, 6(3): 72-78.
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    Geographical network modeling emphasizes the network topology between the nodes and links withinthe logical networks and the semantic manipulation process.But the classical GIS vector data representation isbased on planar graph primitive arc-node data models,which emphasizes geometrical representation.In this paper,the authors introduce a feature based GIS conceptual modeling method to break through the restriction of planar enforcement.To this end,a feature based geographical network model is developed and the characteristics and application issues are discussed.The author separates the network topology from the geometrical dataand argues that network topology is not always dependant on geometrical data although different copies of network topologies can be derived from a same geometrical network.Geographical network topology is differentfrom geometrical topology.Most of network modeling and analysis is based on derived network topology.For theimplementation of geographical network,the integration of object oriented methods and database technologies isfirstly discussed,the difference between classical relational models and object oriented models is then comparedin geographical network representation,and the advantages of object oriented methods for geographical networkroute system representation,dynamic segmentation,and network connection rules are analyzed lastly.It is argued that the feature based object oriented approaches are powerful for complex network modeling and deservesdetailed research and development in network operators,extended structural querying language,and multi-scaledatabases implementation.
  • ARTICLES
    A Study on the Land Potential Productivities in the Yellow River Delta Based on GIS and Landscape Units
    FANG Meng, LIU Gaohuan
    2004, 6(3): 79-83,2.
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    On the basis of a previous research on potential agricultural productivity,the land potentialproductivities in the Yellow River Delta(YRD) were studied with geographic information system(GIS) and YRDGIS databases which include spatial databases and attribute databases.At first,multiple factors influencingland fertility are expounded,then using the mechanism methodology and computing models the land potentialproductivities are computed,including:photosynthetic productivity,photosynthetic thermal productivity,climaticproductivity and agricultural productivity.The characteristics of numeric value disperse and spatial distribution ofland potential productivity in the Yellow River Delta are analyzed through classification statistics and classification mapping.Finally,based on the result,it puts forward respective proposals to develop the landpotential productivities in the Yellow River Delta.
  • ARTICLES
    The Applications of LODs to the Virtual Reality of Mining Area
    LENG Hailong, BIAN Zhengfu
    2004, 6(3): 84-89.
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    This article firstly introduces the applications of LODs.Then particularly expatiates on the categoriesof LODs-based database expression and the theory of morphing between the levels of LODs that can make themodels switch smoothly.In the application aspect,the LODs technique was firstly employed to several models ofDazhuang Coal Mine,which preferably resolved the problems of visual discontinuity and image leap when ex-ploring the original models.Secondly,the VRML was employed to the LODs of network release models,whichpreferably resolved the problem of discontinuity of models when exploring in IE explorer.
  • ARTICLES
    Applying the Bezier Curve in Creating Tree Geometric Model on Virtual Forest
    SHI Song, YU Qizhi, CHEN Chongcheng, ZHU Quanfeng
    2004, 6(3): 90-93.
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    Digital landscape models require abstraction and simplification for realistic landscape.Tree geometricmodel and DEM are two elements in virtual forest.The tree geometric model is very important to forest GIS.Inthe process of model creation,the shape of trunk and branch have outstanding meanings.Because of theircomplexity,plant models used in computer graphics are usually created with procedural methods.A difficultproblem is the interactive control of these models:a small number of parameters is insufficient to specify plantcharacteristics,while a great number of parameters are tedious to manipulate and difficult to comprehend.Asthe shape of an actual tree is diverse,it is impossible to represent all kinds of trees in a special single curve.Toaddress this problem,the Bezier curve which is based on control points is introduced to depict the shape oftrunk and branch.And a OCX control is made to draw the Bezier curve,the result shows the manifold shape oftrunk and branch can be depicted by this method.It has many advantages such as conveniences and celeritywith good visualization effect.
  • ARTICLES
    LFF-based Image Fusion for Land Use Monitoring
    WU Lianxi, YU Shuigen, LIU Xiaomei, SU Xiaoxia
    2004, 6(3): 94-98,2.
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    Remote sensing technology is a highly efficient method applied to investigate rapid land use change.We might acquire detailed land use situation from the fused production of multi-source RS data at least cost.These conventional fusion methods such as HSI transform,Brovey transform and principal components transformcould merge two optical image data of different resolutions——a high spatial resolution panchromatic image anda multi-spectral image at low spatial resolution.However,these fusion methods required same or analogousspectral response range between the high spatial resolution panchromatic image and the low spatial resolutionmulti-spectral image.This paper brought forward an improved fusion method called LoG Filter Fusion(LFF)based on HSI transform,that could merge different kinds of optical image data with different spectral responseranges of multi-source RS data.LFF arithmetic was put forward in this paper,that is,firstly to filter on the highspatial resolution panchromatic image with LoG filter,and then to substitute the intensity component throughHSI transform to engender the LFF image by HSI invert transform.The result of analysis on these fused imagesshowed the gray variance index of LFF fusion method is higher than HSI transform,the color of LFF image isanalogous to the low spatial resolution multi-spectral image,so the LFF fusion method is more excellent at thespectrum preservation capability than HSI transform.And the classification accuracy of the LFF image is 5.68% higher than HSI image.
  • ARTICLES
    Satellite Remote Sensing of Land Use Inter-annual Dynamic Change in Xiamen,China
    CHEN Benqing, XU Hanqiu
    2004, 6(3): 99-104,127.
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    Three land use classification maps of Xiamen in SE China in 1989,1995,and 2000 with their changeconversion matrixes were obtained using the multi-stage classification and the change detection(post-classifica-tion comparison)techniques.The result clearly reveals the land use changes in Xiamen during the 11-yearstudy period with rapid economic development and urbanization process.The land use has changed significant-ly,especially in the main land use types such as the built-up land,the arable land,and the forested land.Alarge amount of arable lands are replaced by the built-up lands due to urban expansion,resulting in not onlythe decrease of quantity but also reduction in quality of the arable lands.Analysis revealed that the main driv-ing forces causing these changes in Xiamen include the progress in industrialization and urbanization,the popu-lation growth,and the topographic environment.The study finally concludes that dynamic monitoring of land useinter-annual change can rapidly and efficiently identify the characteristics and the inherent rules of land usechange of the city by using multi-temporal and muhi-spectral resolution remote sensing images,with a combi-nation of geographic information system(GIS)and global position system(GPS)technique,and the result canserve as a reference for decision-making and urban planning of the local government.
  • ARTICLES
    Application of RS Technology in the Research of Oasis Dynamic Change
    CUI Weiguo, MU Guijing
    2004, 6(3): 105-107,125-127.
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    Oasis,an important area in arid zone,is active,dynamic and related with spatial position.Among allthe issues,oasis evolvement is the core.Basing on the study of the characteristics and rule of oasis changes,the following properties are obtained:(1)Oasis changes include attribute change(compostion,fabric,function,etc.)and the space change(shape,borderline,position,etc.).(2)Oasis change is an active and dynamic pro-cess,which does not take place in the past,but also at present and in the future.(3)Oasis change relates toenvironmental science,geology,spatial information science,ecology,etc.,so oasis change research is a muhi-disciplinary integrated research.The content of oasis change research includes the attribute research,positionchange research,evolvement processes research,driving force research and mechanism research.RS(Remote Sensing)which is a high-technology has been developed quickly and been used widely dur-ing these years in the field of resource investigation,environment monitoring,etc.In this paper,after a briefintroduction of the oasis change,the oasis change research takes Manas oasis as an example for analyzing theapplication of RS technology in the research of oasis attribute change and its spatial position transference.Themethod using RS technology and the theory of physiognomy and geology to study oasis space-time change pro-cess that took place in the past is discussed.
  • ARTICLES
    Study on the Progress and Application of High Resolution Remote Sensing Technology
    ZHU Guangliang
    2004, 6(3): 108-110.
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    Based upon a detailed analysis of the technical progress of high resolution satellite remote sensingrepresented by IKONOS,we have found out three reasons why the satellite remote sensing technology with me-ter resolution was so rapidly developed in the 1990s.Firstly,the international political situation experienced adramatic change with the end of the Cold War,resulting in the ban-lift of this technology,which was strictlylimited to the military departments in various countries.Secondly,the general development of science and tech-nology,and especially the efforts in probing into and testing of the high resolution satellite remote sensing tech-nology by the military departments,have provided favorable conditions for wide spread application of this tech-nology.Thirdly,the increase of users of this technology and the demand of remote sensing data has made it pos-sible for this technology to be commercialized.We hold that the high resolution remote sensing can be widelyapplied to such fields as mapping,urban planning,land management,environmental protection and agriculturaldevelopment.Some insights about the application prospects of this technology have been put forward.Finally,adiscussion about techniques of classification in remote sensing and data sharing is also carried out in combina-tion with the features of such data.
  • ARTICLES
    Ship Detection on SAR Images Based on BP Neural Network
    SONG Wei, ZHAMG Jie, JI Guangrong
    2004, 6(3): 111-114.
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    The imaging abilities and detective advantages of synthetic aperture radar(SAR)are analyzed.According to SAR imaging feature to ships,a method using back propagation(BP)neural network to detect shipson SAR image is put forward on the basis of summarizing the existing ship detection methods.Then morphologicmethod is used to adjust the net detective result.And ship length and width are also extracted depending on theknown pixel size of the SAR image.At the same time,the ship center can be oriented by interpolation usinglatitude and longitude information of the source image.Finally,tests are carried out by this method,whoseresults indicate that the BP neural network has very strong self-adaptability.Although under the circumstancesof low Signal-to-Noise,this method can also get good result.
  • ARTICLES
    Aerophotography for Bird's Eye View Photos Taking of Historical Relics
    QIAN Yuhua, YANG Lin, YANG Jinsheng, LV Zhengzhou, WANG Lei
    2004, 6(3): 115-119.
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    This article introduced the first aerophotographic experiment for archeology using super-light aircraftin China.After having made a fitting experiment plan through correctly comprehending the experiment's de-mands,we have successfully fulfilled this task through skillfully using flight and photographic technology.Based on the super-light aircraft,Landying AD-200Y,and airborne cameras,20 flights have flown for cap-turing the bird's eye view photos from multi-directions of historical relics in Huhhot of Inner Mongolia.799photos were taken by this operation will be useful for archaeologists.The entire procedure we adopted in this experiment is as following:①determining the historical relics item;②using relief map to analyse the basic geographic environment(such as location and landform)of the historicalrelics;③analysing the traffic and weather conditions;④choosing aerophotographic methods;⑤designing flightscheme for the super light aircraft;⑥choosing the camera and the film types;⑦identifying flight safety mea-sures;⑧choosing the base air station and runway;⑨implementing and directing aerophotographic flight;and⑩producing the bird's eye view photos' digital images.
  • ARTICLES
    A Discussion on Triple Joined Point Terra Model and Making the Section of Computer-Aided Regional Geological Survey
    ZUO Renguang, WANG Xinqing
    2004, 6(3): 120-125.
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    It is difficult to collect data for multi-joined-point geologic structure in the system of computer-aidedregional geological survey.To found terra model and mathematic model is the root to settle the difficulty.If wecan do so,we can make Computer-Aided Regional Geological Survey more useful,and make terra working moreconvenient and efficient in the field work.The section plays an important role in geological survey,which makesthe geological phenomenon clearer.As is known the description of triple joined point Terra Model and Making the Section is an important con-tent of the research.In terms of the significance,the text mainly discusses the triple joined point Terra Modedescribed content and sequence.On the basis of those,the author chooses the Visual C++ to design the sectionsystem.In the text,the section system is divided into three function models:data management,map edition and re-sult management.The author details the definitions of the structure of the data and divides the layer.