Research On Mobile Spatial Information Service Based On Hybrid Network Mode

With the development of science and technology, particularlyinformation technology, technology integration of different areas hasbeen greatly promoted. Research and applications is a more active fieldin recent years based on integrating Mobile Spatial Information Service(MSIS) with Geographical Information System (GIS) technology,positioning technology, communications technology and networktechnology,etc.The value of any research can be reflected in actual applications.The paper comprehensively studies and analyzes the composition,characteristics, basic principles, and related technologies such asmobile positioning technology, transmission technology of spatialinformation, mobile computing technology, and constructing technologyof MSIS--Web Service technology. And then the paper presents a set ofsolutions of MSIS based on hybrid network mode, in combination ofbrowser/server with client/server mode, along with Web Servicetechnology and Virtual Private Dialup Network (VPDN) technology. Then,on basis of the solutions, research and development on monitoring systemof the mobile targets is done.The studying contents of the paper include three parts: Firstly,we research on the developing of the common application server platformwith Web Service technology;Secondly, on basis of the commonapplication server platform, we design and implement the solution basedon B/S mode, especially study the developing of the WebGIS serverapplication;Thirdly, on basis of the common application serverplatform, wireless networks solution based on C/S mode is designed andimplemented.Focusing on these three parts, the choosed development schemes areas follows: The implementation of the common application serverplatform uses Microsoft.Net framework, VB.NET developing language andWeb Service technology. WebGIS server of B/S mode chooses ArcIMS 9.1of American ESRI corp., HTML Viewer and ActiveX Connector. Datamanagement platform adopts large relational database management systemOracle9i, and ArcSDE for the professionalization of management. Thedevelopment of wireless private network C/S monitoring system takesadvantage of ArcGIS Engine 9.1.Both of the modes adopt Microsoft.Netframework as development platform and VB.NET as development language.In short, the functions of applications of two modes can be summedup in six parts: user authority management functions, the basicoperation functions of the map, enquiries and analyses functions of themap, positioning and monitoring functions of mobile targets, themilitary plotting functions, and the repeating functions of thehistorical tracks.The results of this research are as follows:Firstly, achievement of the common application server platform withWeb Service technology provides a simpler, more unified andcross-platform mechanism for mutual visits. The platform completes thefunctions as follows: the GPS location information services, gpsOnelocation information services, user authority management and businessinformation management for the whole system.Secondly, the B/S monitoring system of mobile targets based on thecommon application server platform is implemented. The system finishesthe expected goals and now is being tested in subordinate units ofcertain government department in Beijing. And practice proved that thesystem is stable and efficient, and have better flexibility and securityto meet the actual operational requirements. The system has gotimportant practical value.Thirdly, the C/S monitoring system of mobile targets based on VPDNis realized on the basis of the common application server platform. Thesystem meets the operational requirements of certain governmentdepartments in Beijing, mainly includes the functions as follows: basicoperation functions of spatial data, analysis and enquiry functions ofspatial data, users and business information management functions,positioning and monitoring functions, the military plotting functions,and repeating function of track and military plotting history. The mainfunctions of the system have now been finished, and it is expected thatthe system will be soon operational, and monitoring terminalssubsystems will be equipped with slab computers in the office membersof the government departments.Fourthly, this research solves the problem that the gpsOne terminalneeds a long positioning time. The locating time descends from 90seconds to 16 seconds. The solution of this problem makes it very easythat a series of problems such as slowly map renewing and monitoring,arising from the gpsOne locating speed.Fifthly, in the course of research and development of B/S system,the paper also solve some problems as follows: simple installationmethods of ArcIMS servers, how to get the current scale of the map, howto convert the map projection in ArcIMS development, how to add Eya imagedata in ArcIMS map configuration, and how to realize to enquire a dynamiclayer.The paper researches and designs a set of practical, efficient andsafe solutions of MSIS, which integrate GIS technology, GPS positioningtechnology, gpsOne positioning technology, VPDN technology, WebService and other advanced technologies. And on this basis, the papersuccessfully achieves the monitoring system of mobile targets based onhybrid network mode, meeting the operational needs of certaingovernment departments in Beijing. The system will give the governmentdepartments and the corresponding industry departments a strong,data-based, dynamic monitoring and management tool for mobile targets,and promote enterprises to develop towards integrated and intelligentdirection. Therefore, the system will greatly increase the efficiency,and its technology and technology schemes have the larger referencevalue for the development of later similar systems at the same time.