249 
5045700.00-:, 
5045400.00— 
5045300.00—-. 
5045100.00-^-. 
5044300.00-j? 
5044800.00- 
5045600.00- 
5045500.00- 
5045000 
5044700.00- 
1602300.00 
160250C00 
1602700.00 
1602900.00 
1603100.00 16G3300.CK 
-50.00 to -7.00 
-7.00 1D 7.00 
7.00 to 30.00 
Fig. 5 - DEM error plot on system B (5 m grid, 50 m support grid) 
Acknowledgements 
The authors are grateful to Mr. Quecchia of the 
Comune di Botticino and to Rossi Italia for providing 
image data and the reference DEM. Thanks go also to 
Martin Zurn from JRC for scanning the images. 
Finally, the Province of Brescia is aknowledge for 
allowing the publication of the results. 
References 
Ackermann F. (1995) Some Considerations about 
Feature Matching for the Automatic Generation of 
Digital Elevation Models. OEEPE Publication n. 33. 
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Bacher U. (1998): Experimental Studies into 
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Arch, of Photogrammetry and R.S.. Vol. XXXII. Part 
4. 
Baltsavias E. P. (1996): Digital Ortho-Images - A 
Powerful Tool for the Extraction of Spatial- and Geo- 
Information. ISPRS Journal of P&RS. Vol. 51, No. 2, 
pp. 63 - 77. 
Baltsavias E., Kaeser K. (1998): DTM and Orthoimage 
generation - A thorough analysis and comparison of 
four digital photogrammetric systems. Int. Arch, of 
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Duperet A. (1996): Automatic Derivation of a DEM to 
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219. 
Gruen A., Baltsavias E. (1985): Adaptive Least 
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