Wolfgang Reinhardt
University of the federal armed forces
Department of civil engineering and surveying
Institute for Geoinformation and land development
Werner-Heisenberg-Weg 39
D-85577 Neubiberg
Tel.: (89) 6004-2450 / 3435
Fax: (89) 6004-4090
E-mail: Wolfgang.Reinhardt@unibw-muenchen.de
 
Internet technology is among others (e.g. CORBA, OLE/COM) the most important enabling factor for interoperating geographic information systems. This paper discusses some aspects of the impact of internet technology in the field of geographic information systems and mainly its usage in applications. The last item is illustrated by some examples.
 
There are mainly two issues which are considered in this paper. In the first section - as an introduction - the evolution in the development of GIS products and the new software architecture in the internet environment (GIS product architecture) is discussed. In the second section of the paper some of the new possibilities of interaction with the user and the use of this technology in specific applications (Internet applications) are presented.
 
The simple possibility of providing raster maps in the web is not considered here. In the section ´GIS product architecture´ an overview is given how GIS can work in the internet environment. The concept of GIS web servers and the communication between web servers and clients using CGI scripts, java aplets or something similar is roughly discribed.

In the second section the work of three relevant projects of our GIS group are introduced:

GIS INTERNET CLIENT

In one project we have developed an GIS Internet Client to view data from different servers. This client is completely written in Java and is able to zoom and scroll GIS data in rasterformat. The communication with the web server is based on CGI technique in the moment. The efficiency and the limitations of this solution as well as possible extensions are also discussed here.

ALPINE HIKING GUIDE

In another project we have developed an alpine hiking guide using internet / Java technology which helps tourists planning their outdoor activities in alpine regions. This projects shows the advantages of multimedia applications using texts, photos, video-clips for such purposes. This guide provides the data of a scanned topographical map, terrain model data (heights) and streets and foot paths (vector data). As a sophisticated routing solution is available the user is able to plan hiking or cycling tours interactively with regard to the time he wants to spent, to maximum heights and slopes and other parameters. In addition the user can receive current data via hyperlinks from the internet e.g. about weather-forecast, snow state and others.

3D PRESENTATION OF TERRAIN SECTIONS

The goal of this project was the presentation of terrain features and the terrain in 3D also enabling walks through the region. For this reason photogrammetrically measured terrain features and a digital terrain model have been made available and have been converted in VRML format. Afterwards different standard VRML browsers have been used to visualise the data. In order to provide information on the orientation of the viewer (coordinates of the viewers standpoint and his viewing direction) and to visualise this information a Java extension for the standard browser has been written. In the last chapter the usage of the internet technology and his advantages and limitation as well as necessary extensions are discussed also.