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29-1143. 
INTEGRATION OF HIGH RESOLUTION DIGITAL ELEVATION MODELS IN 
3D-GIS-APPLICATIONS OF THE ENVIRONMENTAL INFORMATION SYSTEM OF 
BADEN-WÜRTTEMBERG 
D. Hilbring 
Institute for Photogrammetry and Remote Sensing, University of Karlsruhe, Englerstr. 7, 76128 Karlsruhe, Germany, 
hilbring@ipf.uni-karlsruhe.de 
Commission IV, WG IV/6 
KEY WORDS: High resolution, DEM/DTM, Threedimensional, GIS, Application, Visualisation 
ABSTRACT: 
This paper describes the integration of high resolution digital elevation models, currently acquired by the administration of Baden- 
Wiirttemberg, a state in Germany, in two example 3D GIS applications of the Environmental Information System (UIS) of Baden- 
Württemberg. 
The combination of the high resolution DEM with the area-wide data acquisition in Baden-Württemberg leads to a great amount of 
data, which needs to be handled. Thus the paper starts with a discussion about the data handling. The paper describes techniques for 
the preprocessing of the data as a prerequisite for the management of the data with the raster tiling approach in the database. The next 
part of the paper concentrates on techniques for the visualization of the data in a GIS system. These techniques are used in both 
example applications, discussed in the following part of the paper. Both examples show the successful integration of high resolution 
digital elevation models into 3D GIS applications. 
1. INTRODUCTION 
The administration of Baden-Württemberg is currently 
acquiring an area-wide high resolution Laser scanner digital 
elevation model. The resulting one and five meter DEM will 
be included into 3D GIS applications of the Environmental 
Information System (UIS) of …Baden-Württemberg. The 
combination of the high resolution DEM with the area-wide 
data acquisition in Baden-Württemberg leads to a great 
amount of data. The goal is to include these masses of data in 
a usable manner into two different example applications of 
the Environmental Information System. The example 
applications are developed for the Ministry of Transport and 
Environment in the project AJA. The “Landesanstalt für 
Umweltschutz" is attending the technical aspects of the 
development (AJA 2003; LfU 2004). 
The first example application, the DEMViewer, visualises 
textured digital terrain models in different sized regions. 
Depending on the visualising task the region can be small or 
as large as possible. 
The second example application, GeoPro?P is a specific 3D 
application for analysing the ground water table in regional 
areas for planned construction sites. In this case the 
visualised region is usually fairly small. 
Both examples are realised with the means of a 3D GIS 
service included in the base GIS GISterm Framework 
(Hofmann/Hilbring/Veszelka/Wiesel 2000). GISterm 
Framework is a Java based class library for the visualisation 
of space oriented data developed by the Institute for 
Photogrammetry and Remote Sensing and disy GmbH (IPF 
2004; disy 2004). The 3D extension for GISterm, called 3D- 
Service, is based on Java and Java 3D and is developed by 
the IPF (Java 3D 2004). 
The following sections will present methods and techniques 
for processing, managing and visualising high resolution 
DEM data. 
2 
517 
2. DATA HANDLING 
Both applications need terrain data in different sized regions. 
Thus the system needs techniques for providing a 
manageable and visualisable amount of data for every kind of 
bounding region. This mcans we need different data sets as 
basis. 
2.1 Data Basis 
Before the acquisition of the high resolution data started, 
Baden-Württemberg possessed digital elevation models 
derived from aerial views at a resolution of 50 m. This 
dataset is useful for applications using large regions. The new 
Laser scanner models provide high resolution data, which are 
necessary for applications using small regions. 
Let us have a look at the data amount we are talking about in 
the high resolution Baden-Württemberg example. The raw 
DEM data is delivered in ASCII-files containing 1 kn? in 
1 m or 5 m DEM resolution. The area of Baden-Württemberg 
is 35 752 km?. That means we have to handle twice as many 
original ASCII-files. Surely the goal is to handle the data in a 
database. In our example the chosen database is the database 
of the Environmental Information System. 
2.2 Concept 
One commonality of all DEMs is the rasterised arrangement 
of the points. In many 2D-Gl-Systems, techniques for 
visualising large amounts of raster data, like topographic 
maps, are already established. A common solution is dividing 
the raster data into tiles and store them as images in a specific 
format in the database (Hofmann, Veszelka, Wiesel 1999). 
The idea is to reuse this technique for managing digital 
elevation models. This section firstly describes techniques for 
the pre-processing of the data. Secondly it describes the 
raster tiling techniques. Thirdly it describes the access to the 
data in the data base.