Links among GIS, Cadastre and ICTs

Josef Hnojil, Marketa Potuckova
Czech Technical University in Prague
Faculty of Civil Engineering
Department of Mapping and Cartography
Thakurova 7, Praha 6 - Dejvice, 166 29, CZ
{hnojil@fsv.cvut.cz, marketa@gama.fsv.cvut.cz}

Abstract: The main topic of the paper is the utilization of ICTs (Information and Communication Technologies) for purposes of geographical information systems (GISs) and cadastral information systems. Overview of current possible approaches to geographical data through the global computer network is presented. The main part of the paper is devoting to overviewing of different software approaches (static, dynamic and platform-independent), and to discussing of their merits and negations. Information security and data encryption are mentioned. The use of modern ICTs when accessing cadastral data is presented. The paper also outlines future activities made possible by the potential broader use of geographical information.

Keywords: ICT, Internet, WWW, GIS, cadastre, electronic commerce

1. Introduction

Information and communication technologies, Internet, intranet, World Wide Web, information security, electronic commerce - all these terms are used very frequently even in cartography, RS, GIS and surveying journals. Many governments realized that their future economics will not function efficiently without the establishment of national information infrastructures. A considerable number of information systems work with geographical information, so geographical and cadastral information systems were also involved in the infrastructures. The activities will lead to broader electronic commerce with geoinformation. This paper briefly explores possibilities of the Internet in the context of geographical and cadastral information systems.

2. Information Superhighway

The term ”information and communication technologies” (ICTs) is used for description of all devices used by information society for decision making and behavior leading to its versatile development. ICTs can be view as one basis for a shift from an industrial to a post-industrial or information society. [1].

In US 1992 elections, there was the first successful campaign that featured support for the development of a new telecommunication infrastructure – an information superhighway. Senator Al Gore had suggested the development of high-capacity computer network in the US senate in 1991, but as Vice President in December 21, 1993, he said: ”Well, today commerce rolls not just on asphalt highways but along information highways.” [2]. In April 1994, President Clinton signed Executive Order 12906 <http://www.fgdc.gov/NSDI/Nsdi.html>, calling for the establishment of the National Spatial Data Infrastructure. Additional information about NSDI can be found from FGDC web site from where the following description was taken, ”the NSDI is defined as the technologies, policies, and people necessary to promote sharing of geospatial data throughout all levels of government, the private and non-profit sectors, and the academic community. Since 1994, many organizations have joined together to define the means and relationships through which data can be more easily shared.” There also exists the searchable documents’ database of all U.S. Government and Military sites in the USA called GovBot

<http://ciir.cs.umass.edu/ciirdemo/Govbot/>.

European governments reacted to US activities concerning information superhighway by marking out the issues of modernizing telecommunication infrastructures and introducing their own programs and metaphors. When comparing these two programs, we can see that the U.S. process is more participatory, open and transparent than its European counterpart [3]. In Europe, the European Information Society forum was established, in contradistinction to the U.S.A. where a number of main participants is higher (Clinton administration, Congress, Federal Communications Commission).

In May 1994, Bangemann Report ”Europe and the Global Information Society – Recommendations to the European Council” was introduced to public. It proposed liberalization measures, arguing that the best support for growth of information markets and services would be open and competitive markets. Since then, a lot of studies and information materials have been published and most of them are downloadable from the server of EC Information Society Project Office <http://www.ispo.cec.be/>.

From long-time view, national information infrastructures would be connected into one seamless global information infrastructure. Then the term ”cyberspace” which was first proposed as fictional only, will become a reality. It is estimated that there were about 70 millions of people with access to the World Wide Web in March 1998 [source: http://www.headcount.com/>], so the number of people with access to the Internet is higher. There is no central authority on the Internet, so exact number is not available. Because of exponential growth of the number of connected computers and users it almost does not matter what the initial number is - in ten years there will be about one billon of netizens.

It is more interesting, that until 1995 many leading software companies, including Microsoft, underestimated the importance of the Internet. After 1995, they started to catch themselves up on the growing information global market.

3. World Wide Web

The most widely used system for hypertext access over the Internet is the World Wide Web (WWW). The WWW uses client-server architecture for distributed hypertext that can be accessed over the Internet. Overview of the system, which was world-widely used for the first time in January 1993 (browser NCSA Mosaic), is described by authors of the WWW in [4].

Hypertext is a term coined by Ted Nelson around 1965 for a collection of documents (or "nodes") containing cross-references or "links" which, with the aid of an interactive browser program, allow the reader to move easily from one document to another. The hypertext approach is used in producing and using encyclopaedias, dictionaries, manuals, handbooks, and online documentation, library catalogue systems, journalism and support of teamwork.

At present, the term hypertext is mostly replaced by the term hypermedia. It means the connection of hypertext and multimedia files (audio, video, animation).

The hypermedial approach is also widely used in geomatics. Electronic atlases and maps are mostly based on the hypermap principle. Hypermap is described as a ”multimedia hyperdocument with geographical access” [5] or as ”geo-referenced multimedia system that can structure individual multimedia components with respect to each other and to the map.”[6]

Advantages of the WWW are be also used in intranets. Intranet is the term used for description of a local area network (LAN) based on TCP/IP protocols, mostly belonging to a corporation. Intranets are used to share information. A intranet’s Web sites look like normal Web sites, but they can be accessed only by employees of a organization. Intranets are much less expensive to build and manage than private networks based on proprietary protocols (Novell Netware and others).

4. Geographic Information Systems

Number of computers connected to networks increases exponentially in every year and so there is the growing need for geoinformation clearinghouses. Advanced activities in this field can be recognized in the USA, Canada, the Netherlands, Sweden and many other countries (USGS National Geospatial Data Clearinghouse NSDI <http://nsdi.usgs.gov/nsdi/> in the USA, CGDI in Canada, National Clearinghouse for GeoInformation <http://www.ncgi.nl/> in the Netherlands). These repositories of metadata are accessible via the WWW and mostly available free of charge.

Open interfaces and standards being developed by Open GIS Consortium <http://www.opengis.org/> should enable a transparent access to various data formats. Desktop GIS and network/internet-centric GIS [7][8] should become a global GIS. This approach is also supported by Yang in [9] because ”no vendor is able to offer a single system for solving all problems in the wide range of GIS applications and is thus forced to create individual subsystems and to divide a complex system into well-defined components.” From long-term calculation the idea of network computers and componentware looks very hopeful, but it depends on users and customers whether they need this approach.

Usage of geoinformation in future [10] can be assumed not only in the Internet but also in:

More other application areas will be certainly found in future, as the geoinformation market will grow.

Today, most of Internet geographical applications are for free of charge. Generally, they are only the first small step to next era of usage of geoinformation on the Internet. Data formats seem to be the most difficult problem with visualizing graphical data via the Internet. (The most frequently asked question is whether raster or vector data format is better. It depends on an approach only because both of them have their advantages and disadvantages.

5. Internet-based approach to geoinformation

All Internet services are based on the client-server architecture. At present, any of WWW browsers does not internally support a vector data format. The situation should change in next versions of web browsers. In January 1998, Microsoft announced that in version 5 of its Internet Explorer will be implemented a support of vector data. Today, most of vector-based internet applications exact from a user to download and install commercial software. Although it is not technically difficult (and a client-side software is for free), it is not a good approach from a long-term view.

A static approach is the approach when the application is programmed in statical way - no data are then available from a geographical database. This approach is mostly overcome and in many cases are dynamic and platform-independent approaches used.

 

Steps when applying the raster file architecture:

A user does not need to install an additional software (plug-in module) in her WWW browser. Every graphical oriented browser is capable to display an raster image file (GIF, JPEG). In raster-based systems it is possible to create hyperlinks on all map objects.

In vector file architecture

In vector file can be used different layers and additional information can be allocated to every object (polygon, area,…). This approach is close to ‘classical’ geographical information systems. On client’s side must be installed an additional software (sometimes it is solved with ActiveX controls in case of Internet Explorer). Each time the user need to make an operation over the map (zoom, pan), there must be established a new connection with the server, and all the described process must be repeated again.

Meta vector architecture

is similar to vector file architecture. It uses metadata files containing additional information about type and location of data that are needed to display competent maps. When user zooms or pans, instead of downloading whole map, only new data are transferred from the server. Disadvantages of the meta vector architecture are the same as they are in vector file architecture.

Platform-independent architecture

is based on Java, the platform-independent programming language. Java is relatively new language, but from user’s view it offers the better solution than raster and vector-file architectures together. In case of Java usage a user needs only a Java-enabled WWW browser. Both commonly used Internet Explorer and Netscape Navigator have the possibility.

6. Cadastral Information Systems

A Cadastre is normally a parcel based and up-to-date public land information system containing a record of interests in land [11]. A cadastral information system based on paper maps and land record books is historically overcome. Nowadays it is common to maintain a cadastral database where all data is stored. Although an access to many cadastral systems is still available only in office hours, there exist an advanced example of cadastral system where is the possibility to access its database via the Internet.

Dutch citizens can use a modem or network to access cadastral databases through IBM Commerce Network. Information about Kadaster in Dutch can be accessed at <http://www.kadaster.nl/>. All data in cadastral database can be viewed and all transfers of data are paid by possible user.

The second example is Terra Bavaria. It is a project lead by a commercial consultancy company Wenninger GmBH and Bavaria Land Survey Administration Office, which want to create an Internet based geodata warehouse [12]. Official and commercial data will become available, including complete cadastral data for the state of Bavaria, Germany. Nowadays, the project is in beta testing and demo data are available from <http://www.geoware.de/terrabavaria/index.html>.

7. Electronic commerce

Web technologies enabled to begin development electronic commerce activities to business companies. The most frequent activities in the electronic commerce are buying and selling over the networks. However, different industry segments are engaged in increased business activities over the networks. The following ”communities of interest” are described in [13] : automotive, healthcare, government, telecommunications, banking, publishing, education and others. The electronic business with geodata can be put into the ‘others’ group. The assumption that 80 percent of all decisions contain a spatial components is assumed in [14], so in the next century can be proposed that geoinformation market commerce will certainly grow.

In [15] is mentioned the research made by market researcher Giga Information Group that U.S. already in 1996 bought $500 billion worth of goods electronically every year. Efficiency is also in the cost of processing a purchase order from $150 to as little as $25. Although an idea of full EDI (electronic data interchange) does not even work in the USA, but it cannot be left out of consideration.

We mentioned already that present applications on the Internet offer mainly information free of charge. Current state is caused mainly by social factors. Citizens are not used to pay for information obtained via the Internet. Digital data can be offered at free of charge or by paying small amounts of money. Commercial products (the best known is MilliCent by Digital) have already been introduced and their capabilities have shown that transfer of microamounts of money is possible. The MilliCent system is based on a principle of payments of microcents for getting information, magazine articles, music, video clips, online games and software with a simple click of the mouse. The MilliCent microcommerce system lets you buy content without having to produce your credit card number or other sensitive financial information to each provider. Instead of credit cards, MilliCent uses electronic tokens called scrip. [Source http://www.millicent.digital.com/]

8. Information security

In context of electronic commerce we have to mention problems with the information security. The term is often confused with data encryption. Information security is more complex task - users’ authentification, configuration management of software and network protocols, design of whole information system, access controls to data devices, firewalls, auditing, security practices of system users [after 16]. From mathematical point of view it is not possible to break current encryption algorithms. Crackers (people who steal information from computers) use other weak points in a system, e.g. ignorance and carelessness of users - and it is the reason for security awareness training.

9. Conclusion

In presented paper the different topics were presented. Together with electronic commerce and developing information infrastructures it is possible to build functional systems with access to geographical information, whether for free or charge.

Complexity of each of topics allowed only to outline advantages and possible problems, more detailed information about social and technical aspects can be found in the references or in magazines and journals. The objective of the paper was to realize the threads among Internet, geographical and cadastral information systems, electronic commerce, and information security.

10. References

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  2. Al Gore: Remarks by the Vice President at the National Press Club Newsmaker Luncheon. <http://www.whitehouse.gov/>
  3. V. Schneider: Different Roads to the Information Society? Comparing U.S. and European Approaches from a Public Policy Perspective. In H. Kubicek, W.H. Dutton, R. Williams (Eds.): The Social Shaping of Information Superhighways. European and American Roads to the Information Society. Campus Verlag/St. Martin’s Press, Frankfurt/New York, 1997
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  7. G. Albaredes: GeoInformation through the Internet. GeoInformatics, Vol.1, 1, 1998, pp.6-7
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  9. H. Yang: Towards World-wide Use of Geographic Information. GIM, Aug. 1997, pp. 31-33
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  11. The FIG Statement on the Cadastre, FIG, Publication No. 11, Canberra, Australia, 1995
  12. H. Wenninger, M.Wandinger: Terra Bavaria. Cadastral Data on the Internet. GeoInformatics, 1998, Vol.1, No. 1, pp. 32-35
  13. A. Umar: Application (Re) Engineering. Building Web-based Applications and Dealing with Legacies, Prentice Hall, 1997, 587pp.
  14. G. Albaredes: 1992 ‘A New Approach: User Oriented GIS.’ In Proceedings of Third European Conference and Exhibition on Geographical Information Systems, in Munich, Germany (March 23-26, 1992), pp. 830-837
  15. J. W. Verity: Invoice? What’s an Invoice? Business Week, June 10, 1996, pp.110-112, <http://www.businessweek.com/1996/24/b347996.htm>
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