The World Wide Web (WWW) provides a distributed, multimedia system which can be used in teaching, research and for administrative functions. Using WWW you can:
The basic hypermedia concepts underlying the WWW was presented by (Conklin, 1987) and (Nielsen, 1990), and in the context of spatial information systems by (Laurini & Thompson, 1992). Conventional paperbased documents and textbooks, as well as conventional databases, have a sequential and hierarchical structure. A non-linearly organized file of text is called a hypertext. Hypertext provides a novel way of directly accessing data which is quite different from the traditional use of queries. 'Control buttons' arbitrarily embedded in a window presentation of the hypertext, and the mouse clicking facility of computers provides access to information in a non-linearly way. Furthermore, not only text and single images can be recorded electronically: music, speech, sound effects, animations, and video sequences can be recorded and played as well. The term 'multimedia' refers to the integration of these materials into a user friendly and non-linearly way.
Stefano Nativi et al (1995) provides an introduction to multimedia information systems applied for remote sensing with further references, including (Fox, 1991) and (Newton et al, 1992). The multimedia information system he refers to comprises five subsystems:
The structure of the communication subsystem, and the Client-Server paradigm presented is part of the WWW technology. However, the communication language of the World Wide Web is different from the solution presented, and extends to support the graphical user interface. Furthermore, while workstations were used for providing a graphical user interface in the Arno project, the WWW technology can do with personal computers as clients.
The use of the web for educational purposes is an issue within a larger academic field which is labled computer assisted learning, computer based instruction, educational technology, intelligent tutoring, or similar. The field is multidisciplinary and draws upon didactics, software engineering, and cognitive science (Laurillard, 1993). A related field is distance learning (Ramalhoto, 1995). The cognitive aspects of learning are addressed by, for example (Dumslaff & Ebert, 1993), and by the The Cognitive Multimedia Project at the College of Computing, Georgia Institute of Technology, Atlanta.
Early experiences regarding computer assisted learning are reported by (Höhle & Stubkjær, 1990; Stubkjær & Höhle, 1991). A special issue on Geographical Iinformation Systems in education addresses the use of computers for education in several papers (Aangeenbrug, 1992). The ISPRS Commission VI (Economic, Professional Matters and Education), addressed the issue in 1994 (Li et al, 1994), and at later occasions. A project on multimedia computer based on-line training for professionals, PRONET, was reported by (Kainz et al, 1996). A survey of information resources for remote sensing which are available on the World Wide Web was presented by (Jürgens & Spitzer, 1995). Ultimo 1996 (?), a Working Group 4 of Commission VI was established on 'Internet Resources and Spatial Data Sharing'.
In the following, the main components of the WWW technology are outlined. A selection of information resources on remote sensing which are available through the WWW is presented. Information on GIS resources are mentioned only if they appear in connection with remote sensing. Photogrammetry is not covered.
Educational technology developed before the WWW appeared on the scene. Authoring systems and conferencing systems now tend to integrate with the WWW. An account of this trend is made in section 4. On this basis, issues which the new technology may raise for university education in remote sensing are presented. A conclusion closes the paper.
2.1 Development
The Internet and the World Wide Web is from a technical point of view a network of computer networks throughout the world which
From an organizational and economic point of view the nodes and links of the net are quite independent. The net originated from US defense interests who from 1969 supported the development of a computer network which would continue operation even if a headquarter was destroyed. The ARPANET was created for the Advanced Research Projects Agency in the 1970s and funded by the U.S. Department of Defense. An outcome of the ARPA efforts was the TCP/IP (Transmission Control Protocol/Internet Protocol) used by the Internet to support services such as remote login (telnet), file transfer (FTP) and electronic mail. The US National Science Foundation (NSF) gradually took over funding of networking services among university super computer centers.
In these years, international and regional computer networks were developed with a variety of protocols and funding schemes. It became possible to transmit electronic post, and to transfer files without being a computer programmer. Also, 'Usenets' with newsgroups emerged: Software was developed to manage electronic post which was tagged with one or more of hierarchically organized labels, as for example, 'news.groups' or 'comp.infosystems.hyperg'. By this means many persons could share views by electronic mail on issues of common interest. The newsgroups are stored collections of messages regarding a common theme, which can be read and downloaded. Another dispatching strategy is applied by mailing lists, where messages are forwarded automatically by e-mail to those who subscribe to the list (Kehoe, 1992).
This Internet became increasingly popular in research circles, also outside the computer science departments, as a mean for research communication. Networks which connected universities and governmental facilities eventually agreed to follow the protocols and other technical standards of the NSF 'backbone'. Some further definitions: A 'backbone' is a high-speed connection within a network that connects shorter, usually slower circuits. A 'gateway' is a dedicated computer that attaches two or more networks and routes packages from one network to the other until the packets can be delivered to the final destination. A 'router' is a device that sends packets from one place to another, paying attention to the current state of the network (Kehoe, 1992).
The interest in the Internet increased dramatically with two events which introduced the World Wide Web: The definition of the 'HyperText Transfer Protocol' (HTTP) and the 'browser' software which provided the human-computer interface to the transmitted files.
The HTTP and the related 'HyperText Markup Language' (HTML)
The second event was when, late in 1993, the Mosaic WWW browser was released by the National Center for Super Computer Applications (NCSA) in Urbane, Illinois, USA, as freeware. The browser made it possible to show integrated text and images, and provided thus a user friendly interface to a wealth of information resources world wide.
(NCSA's Software Development Group you find at)
It became widely used within months, and from March 1995 the traffic following the HTTP-protocol (WWW traffic) counted more than other network traffic such as transfer of files by means of the File Transfer Protocol (FTP). To respond to this popularity, a World Wide Web Consortium was established to develop common standards for the evolution of the Web.
This information infrastructure and the data accessible through it attracted companies and the general public. National telecommunication companies, and new private companies established as 'Internet Service Providers' (ISPs). They made the services of the 'backbone' available to local area networks of companies, and to single computers connected through dialed-up lines and modem. In 1995 the NSF ceased research support of the 'backbone'. In the USA this service was taken over by seven commercial companies, including the BBN Corp. which was involved since 1969, and America Online Inc. a subsidiary of which managed the NSF's backbone. The commercial use of the Internet and the web was further marked by the creation of the Netscape company which developed the popular Netscape browser, and the decision by among others Microsoft and IBM to provide products and services for the web users.
Concerning the information accessible through the WWW no general editing or central management is exercised. Anyone can publish through the net, and the information available is overwhelming. However, the information overload is basically not different from what you experience at a larger university library (and in a library you can get physically lost). The fact that universities played a major role in the development of the net, and the concern of organizations and companies to support their reputation means that enough of information on the web is of good quality.
The problem of navigating on the net has generated concern (Dieberger, 1995). The wealth of information available, the anarchist way the information is provided, and the fascination of the new technology can make surfing on the net a time consuming passion. However, the software provided for surfing on the net, the 'browser', includes tools that assist you in 'keeping your track' back to 'home', and those who are active on the net put great efforts in organizing the information available.
2.2 WWW technology: Tools, and format specifications
The primary tool for a user to access the web is the browser. Browsers are provided by Netscape Inc (Netscape), by Microsoft (InternetAssistant), and by SUN (HotJava). By means of the browser you can download information pages and software, and read text, graphics, animations on standard Windows or Apple computers. You can save the information on disk for later inspection, and print it on laser printers. To support you in the navigation task, mentioned above, the browser
Mention is made of the fact that browsers can be used 'off-line', e.g for experimenting with 'clickable maps' (Stubkjær, 1996), or for prepration of course notes in the HTML format at home.
The functionality of the browser is restricted to the HTML language. A way to overcome the limitations of the HTML language is to supplement the browser with a program which can handle the specialities of a trade or a research area. Such programs are called 'helpers', 'plug-in's, or 'applets'. The reference
A main tool for making use of the resources of the web is search machines which provides reference to web resources in return for search terms. Lycos, AltaVista, and other search machines are, generally, made available by the university. A 'MetaCrawler' which searches through several other search machines is available too, from
It is fairly easy to master the fundamentals of the HTML language and thus become an author of your own home page. A user survey by The Georgia Tech's Graphics, Visualization, & Usability (GVU) Center shows that most authors spent between 1 and 6 hours learning HTML, with almost half spending 1 to 3 hours.
The specifications of the HTML is most easily learned by means of a HTML editor. It may be convenient to explore the fundamentals of the language with free editors like HTMLassistant. However, to master national character sets, larger files, etc. one may prefer a commercial product like Hot Dog Pro by Sausage Software, Doncaster, Australia,
A guide to learning about the World Wide Web in general, and especially the specification of the HyperText Markup Language is through the World Wide Web Consortium.
A short overview of the HTML elements is available,
Few elements of the HTML language are mentioned here to give an idea of the potential of it.
A hypertext is marked up with tags. The following line
The Hyper (link) Reference, or HREF between documents, or sections within documents, are established by means of 'anchors' of the form
The HTML specifications further includes markup schemes for tables (which by the way can be used for layout purposes), for forms where you can input data to a computer program on the server, and for 'clickable maps'. A clickable map is an image file supplemented with an 'imagemap'. An 'imagemap' is a file (or a section of a file) which between
The Virtual Reality Modeling Language (VRML) is a standard language for describing
interactive 3-D objects and worlds delivered across the Internet. For more elaborated treatment of the HTML, and introduction to the related Virtual Reality Modeling Language reference is made to
References to HTML in other languages are available, too, for example in German
Finally, concerning file formats for images on the web (.GIF, .JPG, etc) a starting point is
2.3 Institutional issues
It was mentioned above that the World Wide Web Consortium was established to develop common standards for the evolution of the Web. As the development took place mainly in research circles the aspiration aroused that software and other resources should be made available for use, inspection and further development, at least to the researcher. This idea of providing free (but not necessarily without charge) is implemented by means of the GNU project, and the Free Software Foundation, Inc., Cambridge, MA, USA. 'GNU' stands for "Gnu's Not Unix" (Kehoe, 1992:68) and refers to the development of a complete, integrated software system that is upward compatible with UNIX. The idea includes that the software is distributed with source code, so you will be able to learn about it, port it to your own machine, and to exchange changes with others. The about 6 page GNU General Public Licence, version 2, June 1991, is available at
Research concerning the web is reported among others at the International World Wide Web Conferences, the last being held May 6-10, 1996, in Paris, France.
A Globewide Network Academy (GNA) maintains an online distance education catalogue, and other distance education resources. So far the information available seem not to address specific issues like remote sensing.
Concluding this section you may wonder if the development of the Internet and the World Wide Web is an event which will change the civilization as did once Gutenberg's printing press. The impact on university education is evident.
Information resources on the World Vide Web includes general information, software, and data libraries. General information may be further subdivided into
The each of the categories of information resources may be further classified according to topic, geography, and time. Furthermore, educational software unites data sets with general information, and thus fails to fit into the above scheme. The many possible structuring criteria and combinations illustrates very well the problem of searching for information resources on the web. The problem is amplified by the fact that the material on the web is made available for 'everybody' so that only very basic structuring criteria can be applied, e.g. by using a metaphor of a journey in an imaginary space, shopping in a mall, etc. The following presents examples of general information which is available on the web, and examples of remote sensing education which applies the web.
3.1 General information on the web
The way the information resources are provided, and the lack of common structuring criteria means that the resources on the www is scattered in a chaotic fashion. However, the www technology allows for means to bring a certain order into the chaos. Besides the above mentioned search machines a main organizing tool is The WWW Virtual Library which, among others, provides references to more than 100 subject matter entries like 'Remote Sensing' and 'Educational Technology'. The references are hyperlinks to pages on the web. The pages are prepared by researchers who take an interest in collecting and organizing links to other pages within their field of interest.
The WWW Virtual Library entry on Remote Sensing is prepared by the VTT Remote Sensing Group of VTT Automation, Finland, and available at
An index provides access to the following items:
Furthermore, there are three links to pages on the web which indicate to contain educational resources, e.g. to 'A Joint Education Initiative'.
While the Virtual Library index does provide for a certain order it is by no means complete. One search strategy is to look for institutions within the field concerned, that is remote sensing. A few examples must do:
The Chair of Photogrammetry and Remote Sensing, Institute of Geodesy and Photogrammetry, Swiss Federal Institute of Technology, Zurich, maintains a server which hosts the WWW server of the ISPRS, and, furthermore, provides structured lists and lists of lists to other web sites of interest.
The homepage of ISPRS is
Reference is made to the homepages which the scientific commissions and working groups have established, e.g. Working Group 4, Commission VI ( 1996 - 2000 ) on Internet Resources and Spatial Data Sharing
Besides university bodies also government departments, international organizations, and larger companies provide services to other web users. It is outside the scope of the present paper to survey these. Mention is made, however, of the existence of larger programmes or research projects, as they may collect references to valuable information resources, too. For example, the European Community has funded the CEO Programme for advancing the use of Earth Observation (EO) data. In this context a European Remote Sensing Infrastructure Survey was made.
Another set of programmes relates to the National Information Infrastructure (NII) project of the USA. Several remote sensing programs have been funded by the NASA High Performance Computing and Communications office through the Information Infrastructure Technology and Applications (IITA) research and development program. For example, the above mentioned 'Joint Education Initiative' and the 'Public Use of Remote Sensing Data' (RSD) Program was established to support the National Information Infrastructure(NII) project.
As examples of on-line journals, conference proceedings, and newslists mention is made of the EARSeL Newsletters by the Committee on Earth Observation Satellites (CEOS)
The Fifth International World Wide Web Conference, Paris, 1996, included a Workshop on WWW Access to Earth Observation/Geo-referenced Data. References are given to a position paper and a Workshop Summary
The mailing list IMAGRS-L (Image processing & Remote Sensing) can be accessed by e-mail for subscribing at listserv@listserv.cesnet.cz. To post to the list the address is IMAGRS-@cesnet.cz. See the heading 'LISTSERV and discussion lists..' under the heading '5. Further reading' at the Satellite Imagery FAQ (frequently asked questions) by Nick Kew et al at
3.2 Remote sensing education via Internet or World Wide Web
The examples which was mentioned so far regarded general information. The facilities of the Internet and the World Wide Web can, however, be applied for on-line remote sensing education. Three projects are mentioned which go for this potential, the Remote Sensing Core Curriculum, the IDRISI WWW Tutorial, and the PRONET project.
The National Center for Geographic Information and Analysis (NCGIA) of the USA provided the framework for the preparation, in the early 90s, of material for university teaching in GIS, the NCGIA Educational Program. An account of the NCGIA educational activities is provided by (Goodchild & Kemp, 1992). The material is listed at
By 1995, a NASA sponsored program, the Remote Sensing Core Curriculum (RSCC) was introduced on the web. Among others, the NCGIA supported the program. The objective of the curriculum reads
The Curriculum is being developed, and contributors are invited. The intended audience is 'national and international collegiate institutions'.
Probably the most extensive educational material on remote sensing and GIS which is available on the web is provided by the IDRISI Resource Center Salzburg, Austria. An IDRISI GIS software package was announced in 1987 (Clark university)
The style and content of the first section on Image Processing appears from the following:
For further information, reference is made to (Clark Uni, present volume, 1997).
The PRONET project started 1996 with the objective to develop, test, and validate an integrated telematics network service for the education and training of researchers and professional specialists. Multimedia communication systems based on open standards with applications for tutorials, guidance, and delivery of seminars will, among others, be developed. The multimedia computer aided learning sessions will be based on existing material appropriately adapted to the PRONET specifications. Latest state of the art multimedia system development tools will assist in this matter (Kainz et al, 1996).
Concluding this section one can note that the WWW is being, and to a certain extent has allready been applied for university education only within 2-3 years of availability. This rapid development poses many questions to university staff and management on how to react to and participate in this development. The www pages of a department or university is another 'window' to the world around. Intended or not they reflect a 'world view' of the body concerned.
4.1 An informal introduction
Several series of conferences focus on educational technology. (Stubkjær, 1994) made an informal bibliographic enquiry into the conferences referred to by the contributions to the International Conference on Computer Based Learning in Science, Vienna 1993. Almost 20 different conferences were referred to which illustrates the wide interest in the field. Having participated in several such conferences one can observe different approaches regarding the use of educational technology. The following categorization is made to assist a staff member or department to select an appropriate approach to the issue. You find:
An account of the situation was made at a workshop on The Potential of WWW and Multimedia for Higher Education, held at the Loughborough University, UK, on 13/14 of February 1995. The workshop was addressing the issues in the context of UK higher education, and concerned with making recommendations which would help UK higher education make efficient and effective use of the new tools.
At the conference it was noted that although several Campus Wide Information Systems (CWISs) using WWW were installed, most sites did not have well developed strategies. Furthermore, a need was identified at the workshop for support of those sites in developing servers and strategies based on good practices and experiences elsewhere.
The report i.a. mentions the delivery of courseware for the WWW:
4.2 Development tools
To support the application of computers in education two kind of software have been developed: authoring software, and conferencing systems. An account of authoring software was made by (Höhle, 1993: 187) and by(Stubkjær, 1994). An example of a recent approach was presented at the 5th International WWW Conference (Crespo & Bier, 1996). Their approach is based on uniting the Hypertext Markup Language (HTML), the Common Gateway Interface (CGI) protocol, and a standard programming language, such as C++, Python, or Perl, to a 'WebWriter'. 'WebWriter' is an integrated system for constructing web applications that supports the authoring of web pages by non-programmers. It is developed by Arturo Crespo, Stanford University, and Eric A. Bier, Xerox Palo Alto Research Center.
Conferencing systems aim at managing the interaction between teacher/ institution and students, and developed from correspondence courses. The mere purpose of managing the communication has been combined with the assessment of student achievements. An example of such courseware is the Ceilidh system. Such systems are of relevance for larger student classes, and for student assignments which are of a rather formal structure.
4.3 Examples of experiences
The Ceilidh system, developed by the Erik Foxley et al, The Learning Technology Research Group, University of Nottingham, UK, has now been in use at Nottingham since 1988, assisting in both C and C++ courses to classes of up to 200 students. It is by November 1996 distributed to about 200 sites in 30 countries. The system is developed for a UNIX platform, and released with a number of interfaces, including the WWW. The courses includes C, C++, Pascal, SML functional language, and SQL. Furthermore, a PC Ceilidh, a stand-alone single-user version for C and C++ courses has been implemented without administrative facilities. Current development plans include multi-user secure versions of Ceilidh for UNIX and PC networks, and porting Ceilidh to a WWW platform.
To further illustrate by example an approach to applying the WWW for education, mention is made of experiences made by the Institute of Photogrammetry and Remote Sensing, Helsinki University of Technology (Haggrén, 1996):
4.3 Issues raised by the new technology
Summing up, the computer was applied for educational purposes well before the WWW appeared. A lot of efforts have been made, and some of the successful have been reported. The research field is complicated, as marked different cultures exist, even within science departments in Europe (Stubkjær, 1993). Therefore, much care is needed to assess whether educational experiences can be transferred from one department and country to another. This calls for a discussion within the individual department to find a balance, among others between:
The outcome, intended or not, will be a position
University departments will need to find answers to these questions which fit to their culture, goals and resources.
The paper has presented evidence that the World Wide Web can be used to develop university education. Specifically, resources on the WWW which are of relevance to remote sensing have been identified, and some successful applications of the new technology have been presented.
Restructuring of education is a complex process, also, because the education must be considered in a societal context. Some aspects of this complex were addressed in terms of issues and questions to be addressed by the staff and department concerned.
Concluding, the opportunities of the WWW are there to be exploited. The www technology as such is not difficult to adopt, the problem is how to do it in a way which improves the education. Further research is certainly needed to assess the variety of educational resources and methods which have been presented here, with a view to enhance the quality of university education.
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