- Email: [email protected]
Development of an internet atlas of Switzerland
Computers & Geosciences 26 (2000) 45±50
Development of an internet atlas of Switzerland
p
Daniel Richard* Institute of Cartography, Swiss Federal Institute of Technology (ETH), ETH Hoenggerberg, 8093 Zurich, Switzerland Received 15 February 1998; received in revised form 30 September 1998; accepted 30 September 1998
Abstract Since mid-1996 an Internet atlas of Switzerland has been developed at the Institute of Cartography. It has been designed to complement the multimedia atlas which has been developed at the same institute for about three years. The concept of the Internet atlas is to combine several elements of the multimedia atlas with the advantages of the Internet (interactivity, availability, easy updating). The development of the Internet atlas has been divided into two phases. In the ®rst phase the development of the multimedia atlas should be completed. Existing solutions will be adapted to the Internet and its peculiarities and more adaptive multimedia functions will be developed. Furthermore the Internet atlas will link to the multimedia atlas which should enable a higher degree of awareness. In the second phase of development, the Internet atlas should become an independent product. The special advantages of the Internet will be considered and by connecting actual data and external links a high degree of content could be reached. As opposed to other existing Internet atlases or interactive map servers not only will self-designed maps be made available but also georeferenced data, such as statistics, maps, pictures and text will be presented using a uniform graphic user interface. # 2000 Elsevier Science Ltd. All rights reserved. Keywords: Interactive maps; Internet cartography; Multimedia
1. Introduction During the last two years the Internet has become progressively more popular. As well as e-mail, which is still the most active service, several other services such as gopher, ftp and www are used frequently. In particular, the World Wide Web with its possibilities of interactivity and the ability to display graphical information on screen oers a new ®eld for cartographers (Gartner, 1996). The Institute of Cartography at the Swiss Federal Institute of Technology, with its long tradition in atlas cartography, is developing a new kind of atlas on the Internet (Sieber and BaÈr, 1996).
http://www.geod.ethz.ch/karto/atlas/atlas.html. * Fax: +41-1-633-1153. E-mail address: [email protected] (D. Richard). p
Such an atlas oers several new functionalities which cannot be made available in a printed atlas, such as immediate updating or extensive interactivity. The development of an Internet atlas of Switzerland will be closely tied to the development of a prototype of an interactive multimedia atlas of Switzerland on CDROM. They will both use a similar user interface which has been developed during the last two years. The interactivity of the interface will be combined with the possibilities oered by the Internet and the use of Internet-browsers. 2. Concept 2.1. Graphical user interface The graphical user interface of the Internet atlas of Switzerland is based on a similar concept as the multi-
0098-3004/00/$ - see front matter # 2000 Elsevier Science Ltd. All rights reserved. PII: S 0 0 9 8 - 3 0 0 4 ( 9 9 ) 0 0 0 3 2 - 1
46
D. Richard / Computers & Geosciences 26 (2000) 45±50
Fig. 1. The layout of the Internet atlas of Switzerland with its dierent segments.
media atlas. Its advantages are combined with some speci®c characteristics of Internet-browsers, which oer a high degree of interactivity. Fig. 1 shows the graphic user interface of the Internet atlas of Switzerland. In order to achieve a high degree of functionality and a clear structure, the screen is divided in several segments: navigation (1); interactions (2); map (3) and information (4). If these segments are too small for some applications, there are two possibilities: maps generated using the Macromedia Shockwave2 plug-in can be zoomed in and out or be panned. In the other segments, scroll-bars are added on the righthand side and if necessary at the bottom of the screen. The frame of this layout is given by the Internetbrowser: the top contains the Netscape2-header, where the name of the browser and the name of the active document are indicated. The other part of the top are the border, the Netscape2 menu bar, which allows dierent manipulations like print, copy/paste, quit, go back, ®nd, etc. The bottom contains browser-speci®c information- or status bar, which also shows some important user information. The navigation (1) segment allows the user to pass through three hierarchical menu-layers. The chosen
steps are always useful for orientation and facilitates rapid change to a dierent subject on any of the three layers. In the future another interface with a Microsoft-Oce-compliant menu structure may replace the actual menu in the top segment. In the interaction-segment (2) the chosen subject can be examined in more detail. Links for adding information like text or pictures and other maps are possible. The largest segment is the map segment (3). Maps and pictures are shown in this window which has an aspect ratio suitable for giving the whole of adequate overviews of Switzerland. In the information-segment (4) further information as text, graphics, tables or pictures can be shown (Spiess, 1994). Besides the already mentioned segments it is also possible to open new windows in which to place pictures or other information as seen in Fig. 2(Richard and Oberholzer, 1997). 2.2. Internet connection An important point in the concept of the Internet atlas of Switzerland is the connection to the Internet. Both browser-speci®c characteristics such as the
D. Richard / Computers & Geosciences 26 (2000) 45±50
47
Fig. 2. A new window with a picture is opened and placed over the layout of the atlas.
menu-bar or the information-bar, as well as already existing resources in the Net, like homepages of ®rms and private and public institutions can be used as additional information to the maps oered. By connecting up-to-date information and external links, a high degree of currency can be obtained. Unlike other existing Internet atlases or interactive map servers such as NAIS-Map (http://www-nais.ccm.emr.ca/schoolnet/issuemap/Home.html), Xerox PARC Map-Viewer (http://pubweb.parc.xerox.com/ map/) or Map Maker (http://lorenz.mur.csu.edu.au/ cgi-bin/gis/Map) the Internet atlas of Switzerland not only provides self-designed maps, but also georeferenced data such as statistics, maps, pictures and text which will be presented in a uniform graphic user interface. An example can be seen in Fig. 3. The user of the Internet atlas of Switzerland has the possibility to display the map of the public transport systems in the canton Zurich. A link to the homepage of the Swiss Federal Railway Company then allows users to search for a connection in the interactive timetable in the information segment. That way a user gets more information than he would get from only using a printed map.
3. Techniques 3.1. The HTML-language The recent version of the prototype of the Internet atlas of Switzerland is based on HTML 3.2 (Hypertext Markup Language). This language is the standard language of the Internet and is supported by the most popular Internet-browsers such as Netscape Navigator2, Microsoft Internet Explorer2 or Spry Mosaic2. For the main part of the atlas, only elements which can be understood by HTML 3.2-compatible browsers were used. For special experiments, browser-speci®c HTML tags are used. For example the layer function of Netscape2, which does not work with MS Internet Explorer2, is used on a single page. This is a function with which partly transparent gif images (map layers) can be turned on and o. For an Internet atlas the whole page should be displayed at once and scrolling should not be needed to see all the information. Therefore the size of the atlaspage has to be limited to the size of the screen. Several tests with atlas layouts have been made and only a screen size of 1024 768 pixels (or better) was appropriate to show all of the necessary elements.
48
D. Richard / Computers & Geosciences 26 (2000) 45±50
Fig. 3. The map of the public transport systems of the canton Zurich is in the map section. The interactive link to the timetable of the Swiss Federal Railway Company is in the information segment.
3.2. The frame technology Usually only one HTML page is seen on an Internet browser, but for the Internet atlas with its special layout, it is necessary to display several pages on a screen at the same time. From version 3.0 of HTML it has been possible to use frames. With this technique one can load only one page in which the size of the frames and the choice of pages which will be loaded into them is de®ned. So it is only necessary to write small pages for the appropriate frame. Each coloured element in the previous ®gures is now a separate frame. This has the great advantage that only those parts of the atlas which change have to be reloaded, while the other parts will remain unchanged. This technique helps to load less data over the Net and shortens waiting time for the user. Frame technology does not allow the exchange of more than one frame at the same time on a single mouse click. Because it is often necessary to load several frames at once, the script language, Java-script (not to be confused with the programming language Java), helps to do exactly this preferred action. Next to frames it is also possible to open a new window, where additional information can be shown. Pictures, text or even other Web sites with more
information about a place or an object can be readily included into the atlas. Some of this additional information, mainly text, could also be stored in a database such as Microsoft (MS) Access2 and be ®lled into the page as a response to a request. In Fig. 3, the timetable information of the Swiss Federal Railway Organisation is available beneath a map of public transport possibilities. This can all be done inside available frames. 3.3. Data There are two possibilities to display maps on the Internet: as bitmap graphics (mainly in the GIF or JPEG ®le-format, depending on the kind of graphics) or as vector graphics. Until recently, the second method was possible only with browser plug-ins capable of handling vector data formats. Maps in bitmap format are usually large, requiring a long time for loading and display. They can neither be zoomed in nor can data be exchanged. Only vector ®les such as Freehand2 ®les (Macromedia Freehand2 7) have these advantages when displayed using the Shockwave2-plug-in (http://www.macromedia.com). This plug-in allows users to pan a picture and even zoom in and out. However, the data is still unchangeable. This
D. Richard / Computers & Geosciences 26 (2000) 45±50
feature is only available with Java-applets, small compiled programs which can be implemented in a HTML page. They are not yet available in the Internet atlas, although some tests have been carried out with an applet (Richard, 1997). With the same plug-in as needed for Freehand2 ®les, Macromedia Director2 ®les can also be shown. So, even small movies, animations or games like an implemented puzzle can be part of such an atlas. Another, new data type used in the atlas prototype are fractal compressed images. These so-called ®f-images (fractal compression images by iterated systems, http://www.iterated.com) use a fractal compression method to make the image as small as possible. Furthermore it adds a certain interactivity to the map by adding a right-mouse-button pop-up menu which enables a user to, for example zoom-in to the image. Due to the special compression technique used by Iterated the image is not resolved in pixels, but in a special structure as seen in the zoom of Fig. 4. This structure is more pleasing to the eye than a pixel structure. There is just one argument against the use of .®f ®les on the World Wide Web: to see these images a user needs to download a plug-in for the Web browser (Richard, 1997). The atlas includes several thematic maps about Switzerland and a vast amount of additional information about the maps and the area presented. Also, a map designed as part of a diploma thesis and several student maps have been included. All the maps and information included at present in the Internet atlas of Switzerland represent only a sample of the full poten-
49
tial. Further testing of the existing and new techniques will continue. 3.4. Interactivity To obtain interactivity using a map it is necessary to click on an element of a map and to receive more information about it. This is possible with metamaps or clickable maps, a technique where a map ®le with coordinates is combined with an HTML ®le. A certain action can be achieved with a click on a pre-de®ned area of a bitmap graphic. For example, a new map or a text ®le can be loaded inside a frame. With the help of Javascript it is even possible to obtain additional information in the status bar of the browser when the user moves over a certain area of the map. Almost the same functionality can be achieved by using Freehand ®les. Here the user can click on an element and a new page with the appropriate information is loaded. With the use of Macromedia Director2 or Flash2 movies a certain amount of interactivity within small movies or animations can be achieved, but every step has to be de®ned in advance. If more interactivity is needed the use of CGI script or Java is the only possibility to achieve such a result. As a ®rst experiment with Java a thematic-map applet has been produced. A screenshot of the applet implemented in the Internet atlas can be seen on Fig. 5. Here the user can choose a statistical ®le, a background image and the kind of diagram. Then a the-
Fig. 4. A ®f-®le and an enlarged cutout.
50
D. Richard / Computers & Geosciences 26 (2000) 45±50
Fig. 5. Thematic map of the canton Waadt, produced with a Java-Applet based on a statistic ®le. Area colours: cantons of Switzerland, Pie charts: ®ctive data.
matic map is produced within the next few seconds (depending on computer performance). Furthermore, the userwillbeabletoresize the diagramsandeven alegendwill show up below the map. Unfortunately Java is not as stable as C++ or other programming languages as there are inconsistency problems when using dierent Web browsers. Later, the applet will be developed further so that the user can choose a statistical ®le and a background image from any webserver on the World Wide Web. However, to achieve this goal the Java programming language must be improvedinordertoovercometheproblemsmentioned.
4. Conclusion Development of the Internet atlas has proceeded to a point where a ®rst version could be put onto a test Website in order to perform tests over the Internet. The interface and some maps with their legend, text and additional pictures have been implemented. Until now most maps are still based on bitmap graphics which slow down requests. Therefore further tests with other and new technologies will be performed to display maps as vector-graphics and to improve the existing raster maps. More themes and information, as well as more links to other resources, will be implemented to improve the Internet atlas both thematically and technically.
A ®rst version of the atlas has been available to the public since May 1998 on the Institute's homepage.
References Gartner, G., 1996. Kartographie und Internet. In: SGK (Ed.), Kartographie im Umbruch: neue Herausforderungen, neue Technologien; BeitraÈge zum Kartographiekongress Interlaken 1996, Bern, Switzerland, pp. 239±246. Richard, D., Oberholzer, C., 1997. Development of an Internet atlas of Switzerland. Proceedings of the 18th International Cartographic Conference of the ICA, vol. 2, Stockholm, Sweden, pp. 989±995. Also available at: http:// www.geod.ethz.ch/karto/papers/ICC97/dr/idsicc97.htm. Richard, D., 1997. Entwicklung eines Internet Atlas der Schweiz. Paper for the GeoViSC Workshop, UniversitaÈt MuÈnster, 25. September 1997. Internet-periodical: Geoinformatik Online 3/97, at: http://gio.uni-muenster.de/ or http://www.geod.ethz.ch/karto/papers/GeoVisC/dr/ dr.htm. Sieber, R., BaÈr, H.R., 1996. Das Projekt Interaktiver Multimedia Atlas der Schweiz. In: SGK (Ed.), Kartographie im Umbruch: neue Herausforderungen, neue Technologien; BeitraÈge zum Kartographiekongress Interlaken 1996, Bern, Switzerland, pp. 211±226. Spiess, E., 1994. Some problems with the use of electronic atlases. In: 9th Konferenz der LIBER-Gruppe der Kartenbibliothekare, Zurich.
Development of an internet atlas of Switzerland
p
Daniel Richard* Institute of Cartography, Swiss Federal Institute of Technology (ETH), ETH Hoenggerberg, 8093 Zurich, Switzerland Received 15 February 1998; received in revised form 30 September 1998; accepted 30 September 1998
Abstract Since mid-1996 an Internet atlas of Switzerland has been developed at the Institute of Cartography. It has been designed to complement the multimedia atlas which has been developed at the same institute for about three years. The concept of the Internet atlas is to combine several elements of the multimedia atlas with the advantages of the Internet (interactivity, availability, easy updating). The development of the Internet atlas has been divided into two phases. In the ®rst phase the development of the multimedia atlas should be completed. Existing solutions will be adapted to the Internet and its peculiarities and more adaptive multimedia functions will be developed. Furthermore the Internet atlas will link to the multimedia atlas which should enable a higher degree of awareness. In the second phase of development, the Internet atlas should become an independent product. The special advantages of the Internet will be considered and by connecting actual data and external links a high degree of content could be reached. As opposed to other existing Internet atlases or interactive map servers not only will self-designed maps be made available but also georeferenced data, such as statistics, maps, pictures and text will be presented using a uniform graphic user interface. # 2000 Elsevier Science Ltd. All rights reserved. Keywords: Interactive maps; Internet cartography; Multimedia
1. Introduction During the last two years the Internet has become progressively more popular. As well as e-mail, which is still the most active service, several other services such as gopher, ftp and www are used frequently. In particular, the World Wide Web with its possibilities of interactivity and the ability to display graphical information on screen oers a new ®eld for cartographers (Gartner, 1996). The Institute of Cartography at the Swiss Federal Institute of Technology, with its long tradition in atlas cartography, is developing a new kind of atlas on the Internet (Sieber and BaÈr, 1996).
http://www.geod.ethz.ch/karto/atlas/atlas.html. * Fax: +41-1-633-1153. E-mail address: [email protected] (D. Richard). p
Such an atlas oers several new functionalities which cannot be made available in a printed atlas, such as immediate updating or extensive interactivity. The development of an Internet atlas of Switzerland will be closely tied to the development of a prototype of an interactive multimedia atlas of Switzerland on CDROM. They will both use a similar user interface which has been developed during the last two years. The interactivity of the interface will be combined with the possibilities oered by the Internet and the use of Internet-browsers. 2. Concept 2.1. Graphical user interface The graphical user interface of the Internet atlas of Switzerland is based on a similar concept as the multi-
0098-3004/00/$ - see front matter # 2000 Elsevier Science Ltd. All rights reserved. PII: S 0 0 9 8 - 3 0 0 4 ( 9 9 ) 0 0 0 3 2 - 1
46
D. Richard / Computers & Geosciences 26 (2000) 45±50
Fig. 1. The layout of the Internet atlas of Switzerland with its dierent segments.
media atlas. Its advantages are combined with some speci®c characteristics of Internet-browsers, which oer a high degree of interactivity. Fig. 1 shows the graphic user interface of the Internet atlas of Switzerland. In order to achieve a high degree of functionality and a clear structure, the screen is divided in several segments: navigation (1); interactions (2); map (3) and information (4). If these segments are too small for some applications, there are two possibilities: maps generated using the Macromedia Shockwave2 plug-in can be zoomed in and out or be panned. In the other segments, scroll-bars are added on the righthand side and if necessary at the bottom of the screen. The frame of this layout is given by the Internetbrowser: the top contains the Netscape2-header, where the name of the browser and the name of the active document are indicated. The other part of the top are the border, the Netscape2 menu bar, which allows dierent manipulations like print, copy/paste, quit, go back, ®nd, etc. The bottom contains browser-speci®c information- or status bar, which also shows some important user information. The navigation (1) segment allows the user to pass through three hierarchical menu-layers. The chosen
steps are always useful for orientation and facilitates rapid change to a dierent subject on any of the three layers. In the future another interface with a Microsoft-Oce-compliant menu structure may replace the actual menu in the top segment. In the interaction-segment (2) the chosen subject can be examined in more detail. Links for adding information like text or pictures and other maps are possible. The largest segment is the map segment (3). Maps and pictures are shown in this window which has an aspect ratio suitable for giving the whole of adequate overviews of Switzerland. In the information-segment (4) further information as text, graphics, tables or pictures can be shown (Spiess, 1994). Besides the already mentioned segments it is also possible to open new windows in which to place pictures or other information as seen in Fig. 2(Richard and Oberholzer, 1997). 2.2. Internet connection An important point in the concept of the Internet atlas of Switzerland is the connection to the Internet. Both browser-speci®c characteristics such as the
D. Richard / Computers & Geosciences 26 (2000) 45±50
47
Fig. 2. A new window with a picture is opened and placed over the layout of the atlas.
menu-bar or the information-bar, as well as already existing resources in the Net, like homepages of ®rms and private and public institutions can be used as additional information to the maps oered. By connecting up-to-date information and external links, a high degree of currency can be obtained. Unlike other existing Internet atlases or interactive map servers such as NAIS-Map (http://www-nais.ccm.emr.ca/schoolnet/issuemap/Home.html), Xerox PARC Map-Viewer (http://pubweb.parc.xerox.com/ map/) or Map Maker (http://lorenz.mur.csu.edu.au/ cgi-bin/gis/Map) the Internet atlas of Switzerland not only provides self-designed maps, but also georeferenced data such as statistics, maps, pictures and text which will be presented in a uniform graphic user interface. An example can be seen in Fig. 3. The user of the Internet atlas of Switzerland has the possibility to display the map of the public transport systems in the canton Zurich. A link to the homepage of the Swiss Federal Railway Company then allows users to search for a connection in the interactive timetable in the information segment. That way a user gets more information than he would get from only using a printed map.
3. Techniques 3.1. The HTML-language The recent version of the prototype of the Internet atlas of Switzerland is based on HTML 3.2 (Hypertext Markup Language). This language is the standard language of the Internet and is supported by the most popular Internet-browsers such as Netscape Navigator2, Microsoft Internet Explorer2 or Spry Mosaic2. For the main part of the atlas, only elements which can be understood by HTML 3.2-compatible browsers were used. For special experiments, browser-speci®c HTML tags are used. For example the layer function of Netscape2, which does not work with MS Internet Explorer2, is used on a single page. This is a function with which partly transparent gif images (map layers) can be turned on and o. For an Internet atlas the whole page should be displayed at once and scrolling should not be needed to see all the information. Therefore the size of the atlaspage has to be limited to the size of the screen. Several tests with atlas layouts have been made and only a screen size of 1024 768 pixels (or better) was appropriate to show all of the necessary elements.
48
D. Richard / Computers & Geosciences 26 (2000) 45±50
Fig. 3. The map of the public transport systems of the canton Zurich is in the map section. The interactive link to the timetable of the Swiss Federal Railway Company is in the information segment.
3.2. The frame technology Usually only one HTML page is seen on an Internet browser, but for the Internet atlas with its special layout, it is necessary to display several pages on a screen at the same time. From version 3.0 of HTML it has been possible to use frames. With this technique one can load only one page in which the size of the frames and the choice of pages which will be loaded into them is de®ned. So it is only necessary to write small pages for the appropriate frame. Each coloured element in the previous ®gures is now a separate frame. This has the great advantage that only those parts of the atlas which change have to be reloaded, while the other parts will remain unchanged. This technique helps to load less data over the Net and shortens waiting time for the user. Frame technology does not allow the exchange of more than one frame at the same time on a single mouse click. Because it is often necessary to load several frames at once, the script language, Java-script (not to be confused with the programming language Java), helps to do exactly this preferred action. Next to frames it is also possible to open a new window, where additional information can be shown. Pictures, text or even other Web sites with more
information about a place or an object can be readily included into the atlas. Some of this additional information, mainly text, could also be stored in a database such as Microsoft (MS) Access2 and be ®lled into the page as a response to a request. In Fig. 3, the timetable information of the Swiss Federal Railway Organisation is available beneath a map of public transport possibilities. This can all be done inside available frames. 3.3. Data There are two possibilities to display maps on the Internet: as bitmap graphics (mainly in the GIF or JPEG ®le-format, depending on the kind of graphics) or as vector graphics. Until recently, the second method was possible only with browser plug-ins capable of handling vector data formats. Maps in bitmap format are usually large, requiring a long time for loading and display. They can neither be zoomed in nor can data be exchanged. Only vector ®les such as Freehand2 ®les (Macromedia Freehand2 7) have these advantages when displayed using the Shockwave2-plug-in (http://www.macromedia.com). This plug-in allows users to pan a picture and even zoom in and out. However, the data is still unchangeable. This
D. Richard / Computers & Geosciences 26 (2000) 45±50
feature is only available with Java-applets, small compiled programs which can be implemented in a HTML page. They are not yet available in the Internet atlas, although some tests have been carried out with an applet (Richard, 1997). With the same plug-in as needed for Freehand2 ®les, Macromedia Director2 ®les can also be shown. So, even small movies, animations or games like an implemented puzzle can be part of such an atlas. Another, new data type used in the atlas prototype are fractal compressed images. These so-called ®f-images (fractal compression images by iterated systems, http://www.iterated.com) use a fractal compression method to make the image as small as possible. Furthermore it adds a certain interactivity to the map by adding a right-mouse-button pop-up menu which enables a user to, for example zoom-in to the image. Due to the special compression technique used by Iterated the image is not resolved in pixels, but in a special structure as seen in the zoom of Fig. 4. This structure is more pleasing to the eye than a pixel structure. There is just one argument against the use of .®f ®les on the World Wide Web: to see these images a user needs to download a plug-in for the Web browser (Richard, 1997). The atlas includes several thematic maps about Switzerland and a vast amount of additional information about the maps and the area presented. Also, a map designed as part of a diploma thesis and several student maps have been included. All the maps and information included at present in the Internet atlas of Switzerland represent only a sample of the full poten-
49
tial. Further testing of the existing and new techniques will continue. 3.4. Interactivity To obtain interactivity using a map it is necessary to click on an element of a map and to receive more information about it. This is possible with metamaps or clickable maps, a technique where a map ®le with coordinates is combined with an HTML ®le. A certain action can be achieved with a click on a pre-de®ned area of a bitmap graphic. For example, a new map or a text ®le can be loaded inside a frame. With the help of Javascript it is even possible to obtain additional information in the status bar of the browser when the user moves over a certain area of the map. Almost the same functionality can be achieved by using Freehand ®les. Here the user can click on an element and a new page with the appropriate information is loaded. With the use of Macromedia Director2 or Flash2 movies a certain amount of interactivity within small movies or animations can be achieved, but every step has to be de®ned in advance. If more interactivity is needed the use of CGI script or Java is the only possibility to achieve such a result. As a ®rst experiment with Java a thematic-map applet has been produced. A screenshot of the applet implemented in the Internet atlas can be seen on Fig. 5. Here the user can choose a statistical ®le, a background image and the kind of diagram. Then a the-
Fig. 4. A ®f-®le and an enlarged cutout.
50
D. Richard / Computers & Geosciences 26 (2000) 45±50
Fig. 5. Thematic map of the canton Waadt, produced with a Java-Applet based on a statistic ®le. Area colours: cantons of Switzerland, Pie charts: ®ctive data.
matic map is produced within the next few seconds (depending on computer performance). Furthermore, the userwillbeabletoresize the diagramsandeven alegendwill show up below the map. Unfortunately Java is not as stable as C++ or other programming languages as there are inconsistency problems when using dierent Web browsers. Later, the applet will be developed further so that the user can choose a statistical ®le and a background image from any webserver on the World Wide Web. However, to achieve this goal the Java programming language must be improvedinordertoovercometheproblemsmentioned.
4. Conclusion Development of the Internet atlas has proceeded to a point where a ®rst version could be put onto a test Website in order to perform tests over the Internet. The interface and some maps with their legend, text and additional pictures have been implemented. Until now most maps are still based on bitmap graphics which slow down requests. Therefore further tests with other and new technologies will be performed to display maps as vector-graphics and to improve the existing raster maps. More themes and information, as well as more links to other resources, will be implemented to improve the Internet atlas both thematically and technically.
A ®rst version of the atlas has been available to the public since May 1998 on the Institute's homepage.
References Gartner, G., 1996. Kartographie und Internet. In: SGK (Ed.), Kartographie im Umbruch: neue Herausforderungen, neue Technologien; BeitraÈge zum Kartographiekongress Interlaken 1996, Bern, Switzerland, pp. 239±246. Richard, D., Oberholzer, C., 1997. Development of an Internet atlas of Switzerland. Proceedings of the 18th International Cartographic Conference of the ICA, vol. 2, Stockholm, Sweden, pp. 989±995. Also available at: http:// www.geod.ethz.ch/karto/papers/ICC97/dr/idsicc97.htm. Richard, D., 1997. Entwicklung eines Internet Atlas der Schweiz. Paper for the GeoViSC Workshop, UniversitaÈt MuÈnster, 25. September 1997. Internet-periodical: Geoinformatik Online 3/97, at: http://gio.uni-muenster.de/ or http://www.geod.ethz.ch/karto/papers/GeoVisC/dr/ dr.htm. Sieber, R., BaÈr, H.R., 1996. Das Projekt Interaktiver Multimedia Atlas der Schweiz. In: SGK (Ed.), Kartographie im Umbruch: neue Herausforderungen, neue Technologien; BeitraÈge zum Kartographiekongress Interlaken 1996, Bern, Switzerland, pp. 211±226. Spiess, E., 1994. Some problems with the use of electronic atlases. In: 9th Konferenz der LIBER-Gruppe der Kartenbibliothekare, Zurich.