Research On Mobile-based Spatial Data Organization And Adaptive Positioning Map Services

With development of mobile communication and internet technology, the erawitnesses universal application of mobile internet technology. The mobile internettechnology broadens environment for mobile computing, which facilitates people’s usageof mobile application and access to information from wireless internet any time and anywhere. Nowadays, spatial information-based mobile service has become hotspot in GISresearch especially in field of LBS (Location Based Service) integrated with GPS (GlobalPositioning Systmem) mobile application. The thesis tries to integrate two positioningmodels (GPS modular positioning and mobile station positioning) supported by mobileequipment and feature of CGML (Compact Geography Markup Language) spatial data andprobes into field of self-adaptable mobile positioning and client-side map visualizationbased on CGML. Furthermore, thsis propose a prototype system according to actualdemand. The content of thesis is structured as follow:(1) Organization of mobile-based spatial data. A strategy of spatial data organizationon both server side and mobile client side is proposed according to methodology of spatialdata management. Spatial data management both on server side based on PostGIS andmobile terminal based on nine-tile model CGML cache mechanism enriches and developssystem of spatial data management. On server side, fundamental geographical data in LBSis hibernated in central spatial database. Data query is accomplished by Ibatis mappingtools, which improves query efficiency. On mobile terminal, spatial data is retrieved fromserver by demand. Retrieved data is structured based on nine-tile model as format ofCGML in terminal cache. Mobile terminal cache mechanism based on nine-tile data modelfacilitates map visualization.(2) Map visualization based on mobile terminal CGML cache mechanism. Mobilemap visualization framework is proposed based on analyst of popular mobile mapvisualization solutions. Core of framework in thesis is mobile terminal CGML cachemechanism. In this section, main components of this framework are discussed in detail,which include mobile terminal data query, CGML caching, transformation betweengeographical reference coordination and mobile screen coordination, visualization ofcached spatial data. Organizing CGML as nine-tile model in mobile terminal cache makes it possible to retrieve spatial data directly from cache without interacting with server,which decreases mobile map visualization’s excessive depend on wireless network.Moreover, concurrent spatial data retrieving from cache while map panning shortenswaiting time during map service invoking.(3) Adaptive positioning map service. In this section, current models utilized inadaptive positioning map service are analyzed first. A framework for adaptive positioningmap service is brought forward. Main contents in this framework consist of adaptivepositioning research, precision analyst of two positioning models (GPS-based positioningand mobile base station positioning) and related applications on map server. Precisionanalyst of two positioning models under different environments is brought forward.According to precision analyst result, there exists an optimal positioning model for everysingle positioning. Optimal positioning selection according to both real-time environmentand mobile performance not only encapsulates positioning realization detail for end-user,but also lowers threshold of mobile map service application.(4) Application of adaptive positioning map service. An adaptive positioning mapservice system is designed and implemented. The system is tested and verified byintroducing real application scenario in Fuzhou city. In this application, spatial database ofFuzhou city is constructed. Fuzhou virtual wireless network is established by utilizingMPC MAP TOOL. MPS mobile base station positioning is realized. Mobile map serviceand map visualization based on terminal CGML cache mechanism are implemented. Acomparing evaluation of performance is brought out between proposed system and Googlemobile map. According to result, the proposed methodology and implementation ofadaptive positioning map service is applicable. The proposed solution not only increasesefficiency of mobile map service but also improves universal applicability. Especially, theperformance improvement is highlighted in panning map in client side.