3D QUALITY ASSESSMENT OF HIGH RESOLUTION TERRASAR-X DATA: BARCELONA CASE STUDY
In recent years, Synthetic Aperture Radar (SAR) data is being used intensely for scientific applications and many SAR missions have been accomplished. On the contrary of optical systems operating based on passive sensing principle, SAR technology is capable of providing data independent of weather conditions and time of acquisition under favour of active sensing ability and long wavelength. The most important problem of SAR data was decided upon the resolutuion. However, this problem is overcome with orbitting of TerraSAR-X (TSX) which is considered to be a revolution. TSX can provide high resolution data (up to 1m) covering large areas thanks to three different imaging modes. Today, many scientific studies are performed employing TSX data. ISPRS SAR Interferometry Working Group is also conducting a project that performs quality assessment of digital elevation models generated from TSX data. Within the scope of this project,several test sites are being studied from Turkey, Spain, Germany and Italy.
In this research, many high resolution DEMs are generated using 3m azimuth resolution TSX StripMap (SM) mode images for Barcelona (Spain) and the most suitable one is chosen and quality asessment is performed on it in the context of the aforementioned project. For the study, quality assessment is performed taking into consideration accuracy and visuality components in Barcelona test site that has been partitioned in two sub-areas as a large area with steep and mountainous topography and an urban area. In the application, a photogrammetric reference model that has 10 cm horizontal and 10 cm – 1 m vertical accuracy was used for the verification. The results show that TSX DEM is compatible with all aspects of the topography with the accuracy between ±8-10m.
As another application in the study, Barcelona city model available in Google Earth, which is known to be generated by very accurate LIDAR data, and PSI results of TSX are compared. As a result, it is observed that PSI products and reference data are quite compatible and RMSZ of elevations are around 2,5m.
 Hensley, S., Munjy, R. and Rosen, P., (2001) Interferometric Synthetic Aperture Radar (IFSAR), Digital Elevation Model Technologies and Applications: The DEM Users Manual (David F. Maune, editor), American Society for Photogrammetry and Remote Sensing, Bethesda, Maryland, pp. 142-207.
 Rabus, B., Eineder, M., Roth, A. and Bamler, R., (2003) The Shuttle Radar Topography Mission – A New Class of Digital Elevation Models Acquired by Spaceborne Radar. ISPRS Journal of Photogrammetry and Remote Sensing, Vol. 57, No. 4, pp. 241-262.
 Sefercik, U.G. and Jacobsen, K., (2006) Analysis of SRTM Height Models”, Fifth International Symposium Turkish-German Geodetic Days, Technical University, Berlin, Almanya, 28-31 Mart 2006.
 ISPRS Working Group VII/2 - SAR Interferometry. http://www.commission7.isprs.org/wg2/ (accessed 15 Apr. 2012).
 Jacobsen, K., (2003). DEM Generation from Satellite Data. EARSeL Workshop, 5-7th June, Ghent, Belgium, pp. 273-276.
 Lin, Q., Vesecky, J. F. and Zebker, H. A., (1994) Comparison of Elevation Derived from InSAR Data with DEM Over Large Relief Terrain. International Journal of Remote Sensing, Vol: 15, pp.1775-1790.
 Roth, A., (2003) TerraSAR-X: A New Perspective for Scientific Use of High Resolution Space-Borne SAR Data, 2nd GRSS/ISPRS Joint Workshop on "Data Fusion and Remote Sensing over Urban Areas, 22-23 May, Berlin, Germany
 Raggam, H., Gutjahr, K. H., Perko, R. and Schardt, M., (2010) Assessment of the Stereo-Radargrammetric Mapping Potential of TerraSAR-X Multibeam Spotlight Data. IEEE Transactions on Geoscience and Remote Sensing, Vol. 48. No. 2. pp 971-977.
 Bamler, R. and Hartl, P., (1998) Synthetic Aperture Radar Interferometry. Inverse Problems, Vol. 14, No. 4, R1-R54.
 Sefercik, U., (2010) Generation and Evaluation of DEMs Derived by TerraSAR-X InSAR Images, Doktora Tezi, Bülent Ecevit Üniversitesi, Haziran 2010.
 Sefercik, U. and Soergel, U., (2010) Comparison of High Resolution InSAR and Optical DEMs. EARSeL Joint SIG Workshop: Urban - 3D – Radar – Thermal Remote Sensing and Developing Countries, Ghent, CD, 13 p.
 Goldstein, R. M. and Werner, C. L., (1998) Radar for Geophysical Applications Interferogram Filtering. Geophysical Research Letters, Vol. 25, No. 21, pp. 4035-4038.
 Koch, A. and Heipke, C., (2001) Quality Assessment of Digital Surface Models Derived From the Shuttle Radar Topography Mission (SRTM). IEEE 2001 International Geoscience and Remote Sensing Symposium, University of New South Wales, 9-13th July, Sydney (Australia).
 Sefercik, U. and Alkan, M., (2009) Advanced Analysis of Differences Between C and X Bands Using SRTM Data for Mountainous Topography, Journal of the Indian Society of Remote Sensing, Springer, ISSN: 0255-660X (Print) 0974-3006 (Online), Press: DOI: 10.1007/s12524-009-0044-4, Pages: 335-349.
 Ferretti, A., Prati, C. and Rocca, F., (2000) Nonlinear Subsidance Rate Estimation Using Permanent Scatterers in Differential SAR Interferometry. IEEE Transactions on Geoscience and Remote Sensing 38(5), pp. 2202-2212.
 Liu, G., Buckley, S. M., Ding, X., Cheng, Q. and Luo, X., (2009) Estimating Spatiotemporal Ground Deformation With Improved Permanent Scatterer Radar Interferometry”, IEEE Transactions on Geoscience and Remote Sensing. 47 (8), pp. 2762-2772.
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