CMRT09: Object Extraction for 3D City Models, Road Databases and Traffic Monitoring - Concepts, Algorithms, and Evaluation
future. To not only compare the position of the peaks but also
the shape of the reflection profile, the elevations of the
simulated point scatterers (see Fig. 12) were fed into the
tomographic analysis assuming the same imaging configuration
as for the real TerraSAR-X data. As can be seen from Fig. 14,
the profile matches very well with the tomographic results from
real data (Fig. 13). This example provides a validation of the
SAR simulator in the third dimension by comparing to the
tomographic analysis result using the TerraSAR-X data. In a
further step, it can also be used for validation of tomographic
algorithms by simulating the complex valued measurements of
a data stack with different baseline distributions. 4
Figure 13: reflectivity function extracted from TerraSAR-X
data by SAR-Tomography; intensity peaks estimated
at heights of 3 m and 22.5 m
Simulated tomographic profite from poor provided by SAR emulation
Figure 14: reflectivity function estimated from simulated data
extracted from simulator by SAR-Tomography.
4. SUMMARY AND OUTLOOK
In this paper, a concept and its prototype implementation for 3D
analysis of reflection effects has been presented. 3D model
scenes are sampled by ray tracing techniques for providing
necessary output data in azimuth, slant-range and elevation.
Elevation slices are determined by pixel selection in reflectivity
maps in the azimuth-range plane. Comparison of simulated data
with real SAR data for a selected urban scene provided
promising results. Further studies will have to show whether
simulated elevation data may also support the geometrical
analysis of more complex 3D urban scenes since visual
interpretation of the simulation results is expected to become
more complicated due to the increased number of visible
building features. Meanwhile, the SAR estimator will be
extended for the purpose of validation of tomographic
algorithms.
5. REFERENCES
Adam, N.; Eineder, M.; Yague-Martinez, N.; Bamler, R., 2008.
High Resolution Interferometric Stacking with TerraSAR-X.
Proceedings ofIGARSS 08, Boston, USA
Auer, S.; Hinz, S.; Bamler, R., 2008. Ray Tracing for
Simulating Reflection Phenomena in SAR Images. Proceedings
ofIGARSS 08, Boston, USA
Balz, T. 2006. Real-Time SAR Simulation of Complex Scenes
Using Programmable Graphics Processing Units. Proceedings
of the ISPRS TCVII Mid-term Symposium
Ferretti, A.; Prati, C.; Rocca, F, 2001. Permanent scatterers in
SAR interferometry. IEEE Transactions on Geoscience and
Remote Sensing, 39, 8-20
Fomaro, G.; Serafmo, F.; Soldovieri, F., 2003. Three-
dimensional focusing with multipass SAR data. IEEE
Transactions on Geoscience and Remote Sensing, 41, 507-517
Franceschetti, G.; Iodice, A.; Riccio, D.; Ruello, G., 2003.
SAR raw signal simulation for urban structures. IEEE
Transactions on Geoscience and Remote Sensing, 41, 1986-
1995
Franceschetti, G.; Migliaccio, M.; Riccio, D., 1995. The SAR
simulation: an overview. Geoscience and Remote Sensing
Symposium, 1995. IGARSS '95. 'Quantitative Remote Sensing
for Science and Applications', International, 3, 2283-2285 vol.3
Glassner, A. S., 2002. An Introduction to Ray Tracing. Morgan
Kaufmann, 329
Kampes, B. M., 2006. Radar Interferometry - Persistent
Scatterer Technique. Springer, 213
Mametsa, H. J.; Rouas, F.; Berges, A.; Latger, J, 2001. Imaging
Radar simulation in realistic environment using shooting and
bouncing rays technique. Proceedings of SPIE: 4543. SAR
Image Analysis, Modeling and Techniques IV, Toulouse
Nannini, M.; Scheiber, R.; Moreira, A., 2008. On the Minimum
Number of Tracks for SAR Tomography. Proceedings of
IGARSS 08, Boston, USA
Reigber, A.; Moreira, A., 2000. First demonstration of airborne
SAR tomography using multibaseline L-band data. IEEE
Transactions on Geoscience and Remote Sensing, 38, 2142-
2152
Whitted, T., 1980. An improved illumination model for shaded
display. Commun. ACM, 23, 343-349
Zhu, X.; Adam, N.; Bamler, R., 2008. First Demonstration of
Space-borne High Resolution SAR Tomography in Urban
Environment Using TerraSAR-X Data. Proceedings of CEOS
SAR Workshop on Calibration and Validation
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