Data Content Of 3D City Models

As the most densely distributed district of population, economics, technology, infrastructure and information on earth surface, City is the geographic integration of population and social economy .It is also the most complex and active segment which contains frequent communication among people. With the explosion of city, the problem on city construction and management becomes more and more acute day by day. The complexity of problems and width of information processed before strategists and workers is the obviously great Although the issue on social economy and development is concentrated in some important fields in the past, now the focus is often esthetic, function mode, and apperception about local environment To adapt the development, the three dimension digital representation of city becomes hot issue attracting common attention because of its potential application in management of infrastructure, planning of mobile communication networks, strategy support of city development, emulation of pollution scattering, civil engineering and military supporting. The real three dimension description of city -Three Dimension City Models (3DCM) not only has the reality feeling of traditional VR representation, but also has function of 3D CIS database management and analysis application associated with other social economical information, so it's attention is more and more in the field of city special information.Since its appearance and application in 90's of last century, nowadays 3DCM has already been developed in a certain degree. Many researchers study 3DCM in different aspect, and many data providers can supply 3D models of different cities allover the world. 3DCM can be looked as a kind of non-mature archetype of 3DGIS.The current research mainly includes data capture, data model. data management. visualization and spatial analysis model etc., but in the fields of data criterions and standards there is few systemic and mature study. As a kind of special data, criterions and standards is vital to the application and development 3DCM.Lack of study in mis field has become obstacle of development of 3DCM.In different kind of criterions and standards, data content and its representation of detailed levels are important and basic. On one hand it controls the definition of data to data producer and user, on the other hand it controls the data model, visualization, and study in corresponding field.The content of this paper mainly includes two aspects: (1) data definition based on different 3DCM application classification, which mainly includes definition of classification data, characteristic of classification application, attribute features of 3DCM object, data content catalog and index of different classification.(2) multiple detailed levels definition of 3DCM, which mainly includes characteristics of multiple detailed levels, adaptive data model to 3DCM representation, feasibility analyst of 3DCM multiple detailed levels based on Recognition By Components(RBC) theory, decomposing and composing of object body cell based on RBC theory, unification of texture data and geometry data in 3DCM, definition of multiple detailed levels in different 3DCM application type.(1) data definition based on different 3DCM application classification?Provide application framework of 3DCM. At present the applications of 3DCM in different fields are complex and various. Many application practice proves that data content definition of 3DCM application are based on the direction of application, so lack of 3DCM application classificationframework requires data content standard. Traditional classification of 3DCM application are usually depends on function of application, but this classification is random and can't be unified, so different colony have great difference in understanding the detained functions, and the application type are changing ceaselessly. Considering that 3DCM is a kind of data type which pays attention to information communication based on visualization. This paper provides the viewpoint that 3DCM application plann...