Expression And Modeling Method Of Integrating Continuous And Discrete Tropical Cyclone Data

With the development of geographical observation and data processing,the description of the real world has gradually evolved from static spatial objects to dynamic geographic phenomena and analysis of geographic laws.And geographic data presents characteristics of high-dimension,massive,and spatio-temporal.Due to the difference in the perception of the real world,there are two views called continuous field and discrete object.When the two views reflect in the spatio-temporal data model,they are divided into two types: spatio-temporal field and spatio-temporal object,both of which have their own characteristics on expressing the real world.However,there exits geographical phenomena which combines the characteristics of continuous fields and discrete objects,and tropical cyclone is the typical representative.Thus,how to achieve the integrated expression of these heterogeneous data types and the unified description of complex geographic information will be the focus of this thesis.Based on theory of geographical scene and Geometric Algebra,this thesis discourses the geometric algebra method for the construction and expression of complex scene which is oriented to the process of tropical cyclone.In this thesis,the conceptual model of tropical cyclone scene which is organized by six elements of geographical scene is constructed.Based on multi-vector structure,the integrated expression and unified organization method of multi-source scene data is carried out.And methods for constructing components such as continuous fields and discrete objects in tropical cyclone scene is put forward,as well as calculation and analysis operators for motion processes of tropical cyclone are designed.Based on the above contents,a management and visualization system for tropical cyclone scene is designed,where uses the case data to do experimental analysis and verification.The main research work of this thesis includes the following three aspects:(1)Modeling tropical cyclone scene based on Geometric Algebra;According to the geographical characteristics and expression requirements of tropical cyclone phenomenon,combined with the theory of geographical scene,a conceptual model of tropical cyclone scene expression is constructed.Based on the theory of Geometric Algebra,the integrated expression of multiple scene elements and the unified organization of multiple scene data are realized.A multi-level and multi-temporal expression model for tropical cyclone scene is designed.(2)Construction method of components in tropical cyclone scene;Aiming at the high-dimensional scene data,the organization method of spatio-temporal field and the iteration interpolation algorithm based on Tucker tensor decomposition are designed.On the basis of spatio-temporal field,the method of boundary extraction and object construction for tropical cyclone scene is carried out.With reference to objects of the main field,the construction and expression of tropical cyclone trajectory are realized.(3)Analysis method of the motion process of tropical cyclone.Based on the versor equation,the operator-based expression and calculation method for the motion process of tropical cyclone is carried out.Based on Conformal Geometric Algebra,the calculation operator of spatial metric relationship and topological relationship in tropical cyclone scene is designed.And the dynamic law of the topological relationship during the tropical cyclone movement is discoursed.Based on the theoretical system of geographical scene and Geometric Algebra,the construction and analysis methods of tropical cyclone scene model are carried out in this thesis.Such methods have reference significance for realizing the data organization and scene description of geographical phenomena which both have the characteristics of continuous fields and discrete objects.