Design And Implementation Of Web Map Symbol Service

Map symbol is a graphic interpretation language of map, a main expression form of the earth’s elements on map. Although geographic language has transferred from map to Geographic Information Science (GIS), map symbol is still a GIS main method to portray the features and distribution laws of the earth’s elements intuitively and visually. As an important part of geographical information sharing, map symbol sharing is an inevitable trend, and also will be the future research focus. However, nowadays map symbol sharing is still in the step of sharing among isolated platforms. Nowadays, on one hand, people have developed a number of cartography standards and schema specification; on the other hand, people have tried many shared methods. While, they cannot eradicate differences among GIS software’s map symbol systems. Nowadays, in the background of rapid development of Internet technology and gradual popularization of web cartography application, at the same time, with the growth of web services technology and service oriented architecture, map symbol sharing needs to seek some new techniques and methods to take it from closed to open, from isolation to cooperation, and make use of the new computer interoperability standards to promote the research and development of it.According to the above analyses, taking the map symbol as the research object, facing against the current problems in map symbol sharingthis dissertation takes advantages of web services and introduces the technology into the research of map symbol sharing. This dissertation puts forward web symbol services based on open standard interface, constructs a distributed sharing framework of map symbol, in addition, developed a related prototype system to verify, hoping to offer a new sharing approach for map symbol.The general research outline of this paper as follows:(1) This research is from the perspective of the symbolization function sharing, for the present situation of the simple symbolization configuration function and the limited symbolization methods existing in the current web cartography, introducing the cartography theory, this dissertation imports theory of cartography and analysis ten traditional thematic mapping methods which are boriented to the hand-cartography and simulation-cartography stage. And this dissertation summarizes six kinds of symbolization representation method of the thematic elements to extend and complete current methods of thematic mapping from the substance of symbolization which include the association pattern between visual varies and temporal attribute data, and the scale of attribute data etc.(2) According to the online interactive mapping process, this dissertation puts forward a online interaction mapping model based on data driven and formulates the map symbolization coding specification. In addition, with the model and specification, this dissertation designs web symbol services which support thematic mapping to solve the single representation of map and the faulty thematic mapping function in the distributed condition.(3) Based on the web service technology, this dissertation discusses and constructs a distributed sharing framework of map symbol. Beginning with the perspective of the symbol data sharing, introducing the XML technology, this dissertation designs an XML-based representation mode of symbol data model for sharing which mainly to solve the uniform description of map symbol. Then using Dot Net, SQL Server and other technical schemes, a prototype system for symbol distributed sharing has been built to realize the remote data access and the function call which are independent of platforms and languages in the distributed condition and then validate the feasibility and effectiveness of the sharing framework.