Research On Progressive Transmission Of Vector Spatial Data In Mobile Gis

Progressive transmission of vector spatial data is important for wireless transmission of Mobile GIS. Beginning with the architecture and key technologies for progressive transmission of vector spatial data, this thesis focuses on the research on simplification algorithms and incremental storage model of vector spatial data. On the basis of the analysis of existing vector spatial data reduction algorithms, the author designed a method based on the improved adaptive genetic algorithm to simplify line. By modifying the genetic rates and using effective-ensured crossover and splitting variation operators, the algorithm can obtain the optimal results. On the basis of the analysis of existing vector spatial data incremental storage model, this thesis designed a new multi-level incremental storage model. In this model, the data which is stored in the same level belongs to the same scale. The model’s structure is clear, and it’s easy to operate, so it’s suitable for progressive transmission of fixed scales. In addition, this thesis discussed progressive transmission of multi-entity, including the multi-entity simplification algorithms and the incremental storage model, also including the method to maintain common topological consistency.This thesis designed a prototype system based on the above theoretical researches. By doing the experiments of multi-line progressive transmission, the author verified the feasibility of the research results.In the end, the main research content and results are summarized, and the inadequacies are discussed.