CC BY
45
УДК 528.9:004 Ли Дерен LIESMARS
Уханьский университет Ухань, 430079 Китай
НОВАЯ ЭРА ГЕОИНФОРМАЦИИ
LI Deren LIESMARS Wuhan University Wuhan 430079 China
Email: drli@whu.edu.cn
THE NEW ERA FOR GEO-INFORMATION
Abstract
Along with the forthcoming of Google Earth, Virtual Earth, the next generation of Internet, Web 2.0, Grid Computing and smart sensor web, comes the new era for Geo-Information. In this paper, main features of new Geo-Information era are discussed. This new era is characterized by these features: serviced users are extended from professionals to all public users, the users are data and information providers as well, provided geospatial data are no longer measurement-by-specification but measurement-on-demand through smart sensor web, and services are transferred from data-driving to application-driving. Such problems as out-of-order issues in geographic data collection and information proliferation, quality issues in geographic information updating, security issues in geographic information services, privacy issues in sharing geographic information and property issues on sharing geographic information, which are brought about by new geo-information era, especially problems and challenges confronted in geoinformation science and geo-spatial information industry, are analyzed. Then strategies concerning standards, planning, laws, technology and applications are proposed.
Keywords: New Geo-Information Era, Geo-Services, Digital Measurable Image, Service-on- Demand, Sensor web
1. Why New Era of Geo-Information
In recent years, GIS applications are becoming increasingly widened as requirements for geo-spatial information services grow. Since the concept of GIS was first proposed by Dr. Roger Tomlinson in the 1960s, it has gone through a long process of developments and has acquired remarkable achievements over the last 4 decades. Its application fields include mapping sciences, land use, resources
management, environmental monitoring, transportation, urban planning, precision farming, digital earth, and so on.
Google Map is changing the way we see the world[1]. The forthcoming of Google Earth, Virtual Earth, Web 2.0, grid technology and smart sensor web makes geographic information so popular that not only professional users but also all Internet users can do a variety of work on a uniform spatial information service platform with more and more functions. The openness of geo-spatial information service will boost its application and popularization greatly.
Along with the prevalence of Internet and the emergence of Web 2.0 technology, the promulgation, distribution and publishing of geo-spatial information supported by new technologies are growing at a fast speed. Prof Michael F.Goodchild at the University of California, an academician of the US Academy of Sciences, proposed his idea of “Citizens as Voluntary Sensors” [2] in order to describe the cooperative production of geo-spatial information and the transmission and sharing of geo-spatial knowledge in a more persuasive way. He outlined the prospect of 6 billion residents of the whole world equipped with facilities that are capable of uploading what they consider as important and effective sources of geo-spatial information [3].
Web 2.0, as a human-oriented network, brings new opportunities for geo-spatial information services and it turns passive users into initiative and creative ones. Web 2.0 provides a variety of services with characteristics including experience, communication, variation, creativity and relation. For geo-spatial information services, visualizable services are the basis of experience (such as Google Earth, Virtual Earth, etc.), measurable services ensure variation and creativity and minable services allow for relation among professional applications. This is a great revolution for our traditional geo-spatial information services based on digital maps. Web 2.0 has the potential to transform traditional measurement-by-specification to measurement-on-demand by uploading the external orientation elements of Digital Measurement Images (DMIs) and corresponding measurement
software kit via the Internet[4][5][6] [7]. Measurement-on-demand means when digital
image pairs and their exterior orientation parameters and related software uploaded to Internet on Web 2.0, any end users can measure objects as they like[[8][9]. This function means that the public users are also data and information providers and geo-spatial data are changing from outdated to active participatory services through the integration of smart sensor web and Web GIS. Spatial Data Infrastructure with this kind of geo-spatial information services provides a better solution to users from all walks of life than before10][11].
Google intends to take photos for all streets in the world and develops a street scenes web site, as shown in Figure 1. Thus, all Internet and 3G network users have access to functions on a uniform spatial information service platform. With such a platform, geo-spatial data integrated with other data, such as statistical data, population data, social and economic data, offer comprehensive services of measurement-on-demand for e-government services, e-commerce, public security and transportation industries, and can answer the so-called “4W questions”, i.e., when,
where, what object, and what change. These herald that a new geospatial information era is coming.
The content of this paper is arranged as follows. Section 1 answers the question why a new geo-information era is proposed. Section 2 analyzes the main features of the new geo-information era. Problems and challenges are discussed in section 3. Strategies are put forward in section 4, followed by some concluding remarks in section 5.
Figure 1. Google intends to take photo for all streets in the world and develop street scene site (UK Daily Mail on July 11)
2. Main Features of the New Geo-Information Era
Compared with traditional geo-information systems which are based on electronic maps, main features of new geo-information systems can be summarized as follows:
2.1 Data providers: from professionals to all public users
The differences between traditional geo-information systems and new geoinformation systems from the point of view of data providers are listed in Table 1, in which, such items as data providers, satisfaction of users, mode of service provision, interaction with users are compared in detail.
New geo-information systems provide services not only to professionals but also to all public users. A great many of users require fundamental information which is concerned with professional and individual applications, such as electric power facilities, municipal facilities, security facilities, transportation information, location-based information, and so on. It is a pity that this kinds of information can not be discovered from traditional 4D products directly, that is to
say, traditional 4D products can not satisfy the needs of integrity, richness, accuracy and reality of geo-spatial information which is necessary for social developments. However, in new geo-information era, such information can be acquired from DMIs which are released on the internet according to specific requirements. As illustrated in Figure 2, a user is issuing rental advertisement through ImageMap website platform, and other users can decide whether to bid for renting or not by browsing ImageMap website as well.
Table 1. The differences between traditional and new geo-information systems
from the point of view of data providers
Items Traditional geo-information systems New geo-information systems
Data providers Professionals Professionals and all public users
Satisfaction of users Only fundamental information from data providers More rich and comprehensive information services including maps, images and POI
Mode of service provision Purchase data and software On-line access through distributed systems and interoperability
Interaction with users Passive services Active participation
Figure 2. A user issues rental advertisement through ImageMap website platform, which is helpful for other users to bid for it
2.2 The users: data and information providers as well
In the traditional geo-information era, there exists a clear boundary between data provides and data users. However, in the new geo-information era, this boundary is becoming blurred, as data updating and maintenance can be fulfilled by data providers and data users alike. For example, data users can also upload or annotate new geospatial information in addition to traditional downloading.
The differences between traditional and new geo-information systems from the point of view of data users are listed in Table 2. In Table 2, such items as data
providers, limits, mode of information provision and time effectiveness are compared.
Table 2. The differences between traditional and new geo-information systems
from the point of view of data users
Items Traditional Geo-Information Systems New Geo-Information Systems
Data Providers Professionals Professionals and public users
Limits Clear limits between data providers and users No limits between data providers and users
Mode of information provision Production according to specifications More information through uploading and annotation
Time effectiveness Static Dynamic
Web 2.0 is a revolution and it advocates openness, anticipation, sharing and creativity, which can satisfy individual needs and it turns passive users into initiative and creative users.
According to characteristics of Web 2.0 technology, not only professionals but also public users play the role of data providers in the new geo-information era. Provided data and services are transferred from fixed updating at regular intervals to more popular updating forms in the new geo-information era, i.e., from static updating to dynamic updating. Take ImageMap platform developed by the authors and their team as an example, it offers an annotation function which actualizes communication among map-makers, users and intelligent services. With the convenience of Web 2.0 technology, business users only need to finish registration and payment on this website firstly and annotate their company and brands on image maps. Moreover, registered business users can offer what they think important to consumers on the website regularly and dynamically. Generally, the information contents include business websites, telephone numbers, scene images and text information etc, as shown in Figure 3. At the same time, the annotation function gives access to registered public users to finish free publishing and sharing of location-based images and text information.
A lot of POIs consisting of graphics, images, audios and videos are added. Take ImageMap as an example again. The whole data volume is about 2TB, with more than 300,000 POIs added, which provide geo-spatial information services for individual, business, industry and government users.
Figure 3. The annotation function of ImageMap website
2.3 Geospatial data: from outdated to live through smart sensor web
The differences between traditional and new geo-information systems from the point of view of geo-spatial data are listed in Table.3, in which, data sources, transmission and data features are compared.
Table 3. The differences between traditional and new geo-information systems
from the point of view of geospatial data updating
Items Traditional Geo- Information services New Geo-Information services
Data sources Spatial databases (DEM/DOM/DLG/DRG) Spaceborne, airborne, and ground-based non-contact and contact sensors
Transmission Stand-alone, LAN, Internet The next generation of Internet based on Web 2.0 and 3G mobile networks
Data Features Static Live data
Geo-spatial information services based on specification are not adequate, because data provided from spatial databases are static. In the new geo-information era, the adoption of sensor web technology provides access to services according to specific needs for professional and general users in multimedia and dynamic service environment. For example, for an ITS based on sensor web, mobile sensors on vehicles, fixed sensors at road intersections, captured video data, data in monitoring centers, road condition inspection data and data for emergence are helpful to improve transportation, reduce traffic delay and traffic accidents and decrease gas consumption to a great degree. Furthermore, this kind of sensors can be installed on 3G phones, which has already been completed in Wuhan Urban Grid Management and Service System through uploading by using cameras as data collection tools.
As mentioned previously[4] [12], all aerial and aerospace sensors can be integrated together to build a big smart sensor web. In this way, the accomplishment of real-time data updating, information extraction and services will come true.
Startup info. Of vehicle
Figure 4
Application system in ITS based on sensor web, in which traffic jam can be decreased by about 20%. Traffic delay can be decreased by about 10%~25%. Traffic accident can be reduced by about 50%~80%. Gas consumption can be reduces by about 30%.
Figure 5. Reference Architecture for an interoperable sensor Web
Figure 5 illustrates the reference architecture for an interoperable sensor web[13]. In this architecture, different kinds of data and services can register through registration center and build catalog services. For an end user, there are
three ways to implement data mining and knowledge discovering based on sensor web.
The first one is based on sensor web model. When an end user sends a request on client side, Decision Support System transfers the received request to service chain and search corresponding registered services in catalog services through workflow sequence. Afterwards, registered services acquire information of interest and return it to the end user.
The second one is based on direct feedback of sensor web, which is applied when the corresponding registered service in catalog services can not be found through workflow sequence. In this case, new sensor web feedback is further searched and if the required service can be found, it will be returned to the end user and will be registered at the registration center.
The third one is based on retrieval of digital products, which is also applied when the corresponding registered service in catalog services can not be found through workflow sequence. In this case, required data is further searched through sensor web node instead of sensor web feedback.
In recent years, OGC has already released many standards dealing with smart sensing web such as Sensor Model Language (SensorML), Sensor Alert Service, Sensor Observation Service, Sensor Planning Service, Observations and Measurement, Transdure Markup Language etc.
Figure 6. The system architecture of the future Grid GIS
Figure 6 shows system architecture of future Grid GIS. In this open architecture, the registration of vector data, image data, DEM data and professional data and information is completed by the operating and maintenance personnel of different types of data through registration services.
Service providers of different types of software platforms register their typical functions in the registration center. And then registered functions can be employed for search, integration, sharing of data, information and knowledge through service discovery and service chain integration.
Different types of end users also need to be registered as legal users through User security authentication and after that registered data and information based on grid sharing protocol are available for them.
Figure 7. Geo-spatial information processing and service model of the new
generation
Figure 7 provides a description about the three-layered registration center. The first layer is data registration. The second is software or function registration and the last is user registration.
Figure 8. Registration of geo-spatial information services
Figure 9. Inquire of geo-spatial information services
Figure 10. Service chain setup
Execution
Figure 11. Execution of geo-spatial information services
Figure 12. Results of heterogeneous distributed geo-spatial information services
What follows is the procedure of heterogeneous and distributed geo-spatial information services, as illustrated in Figure 8-12.
Step 1: a service provider register one function (e.g. Binarization Algorithm and its service type is transfer service) on the internet. The annotation of this service is to realize binarization of image and registered supplementary information includes relative information of this service provider (e.g. name, phone number, email, department, address etc.).
Step 2: another provider register another function (e.g. change detection algorithm and its service type is image analyzing) on the internet. The annotation of this service is to realize change detection between two different images. In the same way, relative information of this service provider is also registered as supplementary information.
Step 3: an end user logs successfully and queries the service needed at registration center.
Step 4: the abstract service chain is established through the project requirements and the existing functions. For instance, a service request, such as flooding area analyzing model, can be established as the combination of the following services.
Step 5: the abstract service chain is mapped into the executed service chain.
Step 6: results computed according to service chain are shown, from which the flooding area of Poyang Lake is calculated.
Figure 13. An example of the establishment of an abstract service chain
2.4 From measurement by specification to measurement on demand
The differences between traditional and new geo-information systems from the point of view of measurement are listed in Table 4, in which such items as way of measurement, contents of measurement and precision of measurement are compared respectively.
Table 4. The differences between traditional and new geo-information systems
from the point of view of measurement
Items Traditional Geo-Information services New Geo-Information services
Way of measurement Measurements from provided GIS data Measurement from original image pairs
Contents of measurement fundamental information based on GIS data All measurable information in original image pairs
Precision of measurement Precision from GIS data Multi-scale precision up to cm
In new geo-information era, geo-spatial data in service are DMIs instead of simple image maps. So-called DMIs are digital stereo images appended with six exterior orientation elements acquired by Mobile Measurement Systems (MMSs). With DMIs on the internet accompanied with measuring software kits, measurement of a special object at centimeter level precision is available. Undoubtedly, the overlapping of DMIs with GIS data makes the representation of geographic objects more comprehensive and vivid and facilitates visible, searchable, measurable and minable functions.
In Figure 14, the overlapping of a DMI and an orthoimage of Beijing Bird's Nest, which can support measurement on demand, is illustrated.
Figure 14. A DMI and an orthoimage of Beijing Bird's Nest
2.5 From data-driving to application-driving: Service Oriented
Architecture (SOA)
Service-Oriented Architecture (SOA) is a software system structure that achieves interoperability by packaging the program units which can accomplish a given task. It originates from distributed computing model, promoted by OMG (Object Management Group) and IONA and widely accepted as a standard.
Service-Oriented Integration (SOI) integrates the traditional objects with highly flexible Web Services. SOI provides an abstract interface. Systems are able to communicate with one another by this interface, instead of using low-layer protocols and self-defined programming interfaces to prescribe communication with other systems. The system only needs to appear in a form of service, select the interactive system, make simple discovery and bind with this service at runtime or in design.
Table 5. A Comparison of Data-Oriented Spatial Information Sharing and Service-
Oriented Spatial Information Sharing
Items Data-oriented spatial information sharing Service-oriented spatial information sharing
Outcome form Data of various scales Different granularity service
Invocation interface Data interface Standardized service protocol
The method data updates Periodic renewing Dynamic, continuous, popular renewing as need
Sharing framework By converting the format of data Use the different granularity service
Requirements on operator Professional, experienced personnel Professionals and public
Security Data security protocol or data encryption Provide service contents, service form, service quality on agreement
Flexibility of use Passivity of data searching Registrability and detectability
Integration and Interoperability Difficult in interoperation Can realize interoperation between CORBA, DCOM and EJB with the standard protocol
There is a more intuitive example, as shown in Figure 15. Service-oriented spatial information sharing based on SOA provides data and tools for active measurement-on-demand service for users instead of just information, such as width of roads, position of toll gates, and so on, which is characteristic of data-oriented spatial information sharing.
Figure 15. An example of SOA
3. Problems and Challenges in the New Geo-Information Era
As analyzed above, the new geo-information era provides geospatial information as rich as possible. However, this brings about problems and challenges as summarized below.
3.1 Out-of-order issues in geographic data collection and information proliferation
The out-of-order issues in data collection mean inconsistency among data format, data content, temporal-spatial characteristics etc. which needs to be solved through data interoperability and standardization of various types of original data.
Information proliferation is also a hot issue in the new era, as conflicts surface between the limited storage space and the information contents. Limited bandwidth transfer rate is not compatible with mass information transmission due to unprecedented level of data uploading and downloading in case of emergency. How to distinguish useful and useless data efficiently and how to realize rapid publishing and sharing of geo-spatial information by using the grid technology are major issues.
3.2 Quality issues in geographic information updating
Traditionally, data uploading and updating are implemented based on standards by professionals, while, in the new geo-information era, general users are also data providers. The participation of users is conducive to data updating in real time, but how to guarantee updating quality is a problem, which may be resolved by some effective web standards and online checking tools.
3.3 Security issues in geographic information services
Security issues is also a problem which should not be neglected. For instance, high-resolution images, semantic information, orientation and attribute information about important departments and locations involve data security issue. For one thing, how to set security filter on the Internet for controlling information of high-precision needs to be solved.
3.4 Privacy issues in sharing geographic information
How to protect individual privacy in the web environment has attracted more and more attention nowadays. In the new geo-information era, the spatial information providers release services in the network, the related spatial information would be at high precision. At the same time, the end users may hope to access to the high-precision spatial information.
When high-resolution data are concerned with individual privacy, its protection becomes a pressing problem: how to find the balance between protecting personal privacy and sharing spatial information, when the high-precision data would come down to personal privacy. Currently, of the consensus among many countries is that privacy needs to be protected although divergences exist among different policies. For example, in America, street view websites have been complained that they infringe individual privacy in some aspects and have been warned by Privacy International. Therefore, legislative work is necessary.
3.5 Property issues in sharing geographic information
Although existing policies, laws and rules in surveying and mapping still play important role in monitoring and managing of geo-spatial information, they are not so effective in the new geo-information era.
There are many pressing problems, such as how to specify the ownership of property rights, the contents of property rights and the property location in geographic information sharing, and to satisfy the privacy requirement These require new laws and rules.
4. Strategies
The coming of new geo-information era represents developments and advancement of information technology. Some strategies in terms of standard, planning, law, technology and application are essential for the opportunities and challenges discussed above.
4.1 Standards
New problems in new geo-information era require us to standardize rules and laws in the first instance and then to accomplish geo-spatial information services better.
Nowadays, conflicts between mounting earth observation data and pressing requirements from every walk of life lead to an embarrassing situation where there are more data but little information. In new geo-information era, geo-spatial information services based on DMIs represent s new direction in spatial data services, and its integration with grid services, interpretation services and telecommunication services provides solution to automation, intelligence and popularization of geo-spatial information.
4.2 Planning
In the new geo-information era, such rules as product secrecy protection and product quality control requirements need to be standardized. One typical example is to blur the vehicle identification number or human face by using certain technology. Furthermore, what needs to be standardized includes definition, content and relationship with other basic geographic information products. Also, technical specifications, technical requirements, testing methods, testing rules, distributing format and secrecy requirements of new products should be considered.
4.3 Laws
Such issues as right of privacy, property right and security brought by the new geo-information era need to be resolved by regulations and decrees on the legal level to restrict the behavior of the public. It is important that no infringement to privacy be conducted.
4.4 Technology
According to the characteristics of the new geo--information era, developments and promotion of high-tech with independent property rights on data
obtaining, information processing, and knowledge discovering and intelligent services are indispensable for providing technical support to the construction of generalized spatial information Grid. At the same time, it is necessary to offer solution to information security and removal of personal privacy information automatically and technically.
4.5 Applications
Applications in different industries are encouraged to improve and enrich the annotations to geo-information. That is to say, it is necessary to make the contents and forms of new generation of geo-information as plentiful, vivid and abundant as possible to satisfy various requirements. These can be applied in many fields such as digital cities management, intelligent transport, police, roads, railways and so on. Accordingly, the experiences on data collection, processing, quality control, standardization and application will be accumulated correspondingly.
Figure 16. The task-oriented service mechanism
5. Conclusion
In this paper, the background to the new era of geo-information is analyzed at first. Then main features of the new geo-information era are compared with those of the traditional era. Problems and challenges faced by the new geo-information are then discussed, followed by strategies including standards, planning, laws, technology and applications.
The new Geo-Information era offer unprecedented opportunities for us. We have to develop better tools for storage, management, on-board processing, distribution and service of geo-spatial information in the environment of Grid computing and the next generation of Internet. The goal of the new geoinformation era is to realize one-data collection-many-applications and
measurement-on-demand. We will explore new strategies for handling the challenges.
In prospect, new geo-information era will boost the whole chain of geospatial information industry to prosperity. Geo-spatial information sharing will bring tremendous economic benefits for the whole world. The ultimate benefits of the new geo-information era is to realize geo-information for all.
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Corresponding author:
Name: Deren LI Phone: 86 27 6877 8001 Fax : 86 27 6877 8001 Email: drli@whu.edu.cn
Full postal address: State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, 129 Luoyu Road, Hubei province, P.R. China, 430079
About the first author: Prof.Dr..h.c Li Deren, professor and PhD supervisor of Wuhan University, member of the Chinese Academy of Sciences, the Chinese Academy of Engineering and the Euro-Asia International Academy of Science. He has concentrated on the research and education in multi-media communication, spatial information science and technology spanning remote sensing (RS), global positioning system (GPS) and geographic information system (GIS). His recent research interests include theories and methods for spatial information multi-grid, data mining and knowledge discovery, theories and applications of generalized and specialized spatial information grid, etc.
© Hu ffepeH, 2009
