EuroSDR Projects - Host Ireland

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Figure 4-19: Change map of German data set
4.3.3 A comparison of change detection methods and analysis of results (by Andreas Busch from BKG)
German test data
The German test site selected for this EuroSDR test is located close to Frankfurt am Main. The coloured aerial
image defining the test site covers an area of 2km × 2km. The pixel size on the ground is 0.40m. The topographic
data set to be checked by means of this orthoimage is the ATKIS Basis DLM. ATKIS is the Authoritative Topographic-Cartographic
Information System on the territory of the Federal Republic of Germany. ATKIS is a
trademark of the Working Committee of the Surveying Authorities of the States of the Federal Republic of Germany
(AdV). The most important components of ATKIS are object-based digital landscape models (DLM)
encompassing several resolutions and digital topographic maps (DTK). The ATKIS Basis DLM, i.e. the ATKIS
data offering highest resolution, is produced by the sixteen surveying authorities of the federal states of Germany
and is delivered to the BKG. At the Geodata Centre (GDC) of BKG, the ATKIS Basis DLM is checked with respect
to logical consistency, joined to one homogeneous data set for the territory of the Federal Republic of Germany,
and stored in a database. Since it is the intention of the test to detect differences of topographic reference datasets
and digital images we deliberately selected out-of-date ATKIS data from the archive that do not represent the
current state of data acquisition.
Results
The German test site has been analysed by the automated change detection methods from Austria and from Germany.
The method from Austria is based on the commercial software eCognition and has been developed by the
Austrian Research Center (Kressler et al. 2005) whereas the software from Germany has been developed within a
common project of BKG and the University of Hannover (Busch et al., 2004, Gerke and Busch, 2005).
The results of the two methods are compared to reference results as obtained by a human operator (Figure 4-20).
This is done by means of selected examples and by statistics. As mentioned already out-of-date ATKIS data from