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The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Vol. XXXVII. Part B4. Beijing 2008
emphasize particularly on microcosmic (that is, one the city).
Digital city’s content and frame detail are presented in table 1.
Infrastructure
Network Level
Wide Band Wire Network:
Internet, WWW, Great
Grid;
Wide Band Wireless
Network: Mobile Internet,
WAP, blue tooth, Mobile
GGG;
Wide Band Integrated
Network: Mob, Web, GGG
Data Level
Primary Geodata: DEM,
DLG, DRG, DOM,
Infrastructure Data: City
Constructing, Traffic,
Energy Sources,
Communication,
Social, Economic, Cultural
Data: Population, Resource,
Economy, Culture,
Education, Science,
Technology
Level
Spatial Information
Technology Platform: RS,
GPS, GIS, VR, WebGIS,
Management Information
Technology Platform: ERP,
CRM, SCM,
LBS(WebMIS),
Integrated Information
Technology Platform:
Web(GIS+MIS),
Guarantee
Level
Standard and Specification,
Security, Supervision and
Evaluation,
Policy and Code,
Education,
Application
Engineering
Management
Level
Management about City
Planning, Traffic, Power,
Communication, Accident,
Application
Level
e-Govemment, e-
Commerce, e-CBD, e-
home,
Service Level
Public Information, Mobile
Information,
Decision-making,
Table 1 Digital City’s Content and Frame
2.3 Architecture of Digital city
The construction of digital cities is an integrated application of
modem technologies. Those technologies are Internet,
communication, grid computing, spatial information grid,
Global Positioning System (GPS), Geographical Information
System (GIS), Location-Based Service (LBS), Data Mining,
Virtual Reality, etc. But spatial data infrastructure is its
foundation including a variety of databases, such as spatial
database, image data database, geocoding database, population
database, resource database etc. In the middle tier, there are
some functional servers, for example, spatial data server, spatial
routing and gateway server, geocoding server, attribute data
server. The architecture of Geo-information system is shown in
Figure 1.
Figure 1 Architecture of Digital city
The hierarchical stmcture of Geo-information system includes
mainly five levels, namely the technical level, the data level,
the management level, the service level and the application
level. The technical level involves the technical innovation,
support and guarantee system. The data level includes the
spatial data acquisition, database construction and updating.
The management level indicates the information conformity,
integration and navigation system. The service level is the
socialization and industrialization application service system.
The application level mainly consists of public service,
government affairs and other applications. The authors explain
the five levels as follows:
Application level: realize all kinds of applications involving
government, the enterprise and individuals, constitute spatial
application infrastructure;
Service level: realize services and applies involving spatial
information sharing, constitute spatial service infrastructure;
Management level: realize the integration, fusion and
management of multiple source spatial information, constitute
spatial information infrastructure;
Data level: realize spatial data acquisition, database
construction and updating, constitute spatial data infrastructure;
Technical level: investigate technical innovation, support and
guarantee system, constitute spatial information grid
infrastructure.
On microscopic level it is used for spatial datum frame system,
spatial data processing service system and the foundation of
spatial database. Based on the spatial datum frame, the GPS
continual tracking facility and the difference datum station can
be additionally built, which carries or processes GPS data or
broadcasts to the public.