International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences 
separately. The segmentation of field areas based on the 
gradients in coarse scale of the imagery is carried out using a 
watershed segmentation. In the future, the use of colour and/or 
texture may stabilize the segmentation step. Extracted and 
grouped lines with different criteria in a fine scale and 
additional introduced prior knowledge from GIS-data divide the 
field areas in detailed and improved preliminary results. Finally, 
the derived field boundaries are geometrically refined using a 
snake algorithm. The results demonstrate the potential of the 
proposed solution. Future work will be devoted to the 
development of an integrated network of snakes for all field 
areas of the region of interest together, not only a snake 
initialization for each field separately, in order to improve the 
topological correctness. 
The proposed strategy concerning the extraction of wind 
erosion obstacles has to be investigated in detail and the derived 
results have to be evaluated. In addition, future work will be 
done on the combined evaluation of the different objects 
deriving a refined and integrated final result. 
ACKNOWLEDGEMENTS 
This work is part of the programme GEOTECHNOLOGIEN 
funded by the Federal Ministry for Education and Research 
(BMBF) and the German Rescarch Council (DFG) with the 
publication no. GEOTECH-67. 
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