RESEARCH ON THE PROGRESS AND DIRECTION OF DIGITAL CITY 
MIAO Qian-jun a,c ’*, Li Deren b , TANG Yanli c 
d Tsinghua University, P.R.China 100084 - miaoqianjun@vip.163.com 
b State Key Laboratory for Information Engineering in Surveying,Mapping and Remote Sensing, Wuhan University, 
P.R.China 430070 
^Heilongjiang Bureau of Surveying and Mapping, P.R.China 150086 
KEY WORDS: Digital City, Geo-information industry, Digital Navigation Map, Ubiquity, USDI 
ABSTRACT: 
With the development of information and communication technology, the construction of digital cities has become more feasible. It 
is a powerful way to elevate the city’s strength, to improve the social environment and to promote national sustainable development. 
This paper describes the digital city’s definition, content, frame, architecture, urban spatial data infrastructure (USDI) and discusses 
the relations between digital city and USDI. Based on the significance and strategic prospect of digital city, the paper researches the 
orientation of digital city in details. It also discusses the architecture of digital city according to its development trend. In the last part, 
the five phases of digital city are comprehensively compared and analyzed. 
1. INTRODUCTION 
The construction of digital city is a hot topic on geographical 
information sharing of current geomatics industry and 
consistent with the construction of spatial data infrastructure. 
The geomatics industry is closely related to the construction of 
digital earth, the development of economic society and the 
national defence, therefore the significance of constructing a 
geographic spatial framework is obvious. In order to advance 
the constmction of "digital earth", we need to speed up the 
construction of digital city, especially enhance the service 
ability of geomatics. 
Digital city is an application of digital earth in cities. Integrated 
with modem information technology, digital city will play an 
important role in the process of geomatics development. 
Two of the most powerful drivers of change within global 
economies are the explosion of information technologies (or 
digital technologies) and the shift towards sustainable 
development. Both require us to rethink the nature of products 
and services. Yet there have been surprisingly few attempts to 
assess whether the information and sustainable development 
revolutions will complement or conflict with one another. 
Integration between the two agendas has been slow. Through 
the implementation of Digital cities, this work will offer a 
significant contribution to sustainable development. 
The constmction of digital city has marched into a fast 
implementation stage and simultaneously its process has been 
unprecedentedly promoted. All this . indicates that the 
development of digital city is marching into the breakthrough 
scope and surmounting a historical opportunity. Therefore the 
progress and direction of digital city are worth being discussed 
and researched. 
2. DIGITAL CITY AND ITS ARCHITECTURE 
As a part of the information age, digital city’s functionalities 
are to improve the city services, to elevate the quality of city 
management, to improve the quality of people’s life and to 
maintain the city environment. Therefore digital city plays a 
very important role in the process of sustainable development. 
2.1 Definition of Digital city 
The digital earth is seen as a multi-resolution, three-dimensional 
representation of the planet, into which vast quantities of geo- 
referenced data can be embedded. In other words, digital earth 
is an information nerval meshwork and digital city is a node in 
the nerval meshwork. 
Strictly speaking, the digital city is a dynamic concept, whose 
definition is still evolving. But we can understand it as follow: 
digital city is an open and complex application system based on 
internet technology and city information resource. The digital 
city must integrate with modem information technology and 
communication technology. Its aim is to promote sustainable 
development in the fields of environment, tourism, health, 
technology, sport etc. 
2.2 Content and Frame of Digital city 
As a node of digital earth, digital city content and frame should 
accord with digital earth. The content of digital earth consists of 
infrastructure and application engineering. Infrastructure 
includes Urban Information Infrastructure (UII) and Urban 
Spatial Data Infrastructure (USDI). UII, or information highway, 
is a network layer which consists of communication network 
and computer network. USDI includes techniques, policies, 
standards and manpower resource that are used in acquisition, 
manage, store and distribution of spatial data. Application 
engineering includes management of resources, environment, 
society, economy, region, city and application aimed towards 
government, enterprise and public services. 
Therefore the contents and frame of digital city include 
infrastructure and application engineering. The difference 
between digital earth and digital city is only in scales. Digital 
earth emphasize particularly on whole earth, digital city