FR2.L09 - PROCESSING OF MEMPHIS MILLIMETER WAVE MULTI-BASELINE INSAR DATA
- 1. Applying PSI and Tomographic techniques using Radarsat-2 Spotlight data: a case study for Edmonton area Valentin Poncos (1) , John Dehls (2) , Gianfranco Fornaro (3) , Diego Reale (3) (1) University of Calgary, Alberta, Canada (2) Alberta Geological Survey, Edmonton, Canada (3) Institute for Electromagnetic Sensing of the Environment (IREA) – National Research Council (CNR), Naples, Italy Applying Tomographic techniques using TerraSAR-X stripmap data: a case study for Edmonton area
- 2. Outline DESCRIPTION OF THE GEOLOGICAL LAYOUT ANALYSIS OF THE DEFORMATION RESULTS AT LOW RESOLUTION FULL RESOLUTION DEFORMATION RESULTS ANALISYS ANALYSIS ON THE SEPARATION OF SCATTERERS ON BUILDINGS CONCLUSIONS
- 3. Geological hazards in Alberta
- 5. Location Edmonton’s River valley is inherently unstable due to the action of North Saskatchewan River and very weak clay layers. Coal mining from 1870’s to 1970 lead to further destabilization. River bank collapse and subsidence are significant hazards today.
- 7. Coal mining in Edmonton
- 8. 17 TerraSAR-X acquisitions over the city of Edmonton, Alberta (CANADA) (from 2008. 05. 10 to 2008. 11. 13) Imaging Mode: Single Polarization Stripmap Orbit Direction: Ascending Beam Identification: strip_014 Orbit Number: 10551 Incidence Angle: 44 ° Look Direction: Right Azimuth resolution: 3.3 meters Slant Range resolution: 1.8 meters Polarisation: VV THE TERRASAR-X DATA SET OVER EDMONTON
- 10. Distribution of the Acquisitions 17 Stripmap acquisition from May to November, 2009 Maximun baseline excursion of about 380m
- 11. DATA ANALYSIS BLOCK DIAGRAM ZERO BASELINE STEERING DEM INTERFEROGRAM STACKING ANALYSIS APD AND DEFORMATION ESTIMATION ATMOSPHERIC AND DEFORMATION REMOVAL TOMOGRAPHIC FULL RESOLUTION ANALYSIS Registered SLC Stack LOW RESOLUTION DEFORMATION PRODUCT SINGLE SCATTERERS PRODUCT DOUBLE SCATTERERS PRODUCt
- 12. Tomographic imaging: 3D By synthesizing an antenna also in the slant height direction orthogonal to the line of sight we are able to analyze the vertical structure of the scattering thus extending SAR imaging form 2D (azimuth-slant range) to 3D (azimuth-slant range-slant height) los Slant height Scattering profile
- 13. 4D SAR Imaging (Differential SAR Tomography) N acquisitions with spatial baseline distribution and temporal distribution F. Lombardini, “Differential Tomography: a New Framework for SAR Interferometry “, IEEE Trans. Geosci. Remote Sens., 43, pp. 37-44, 2005. G. Fornaro, D. Reale, F. Serafino, "Four-Dimensional SAR Imaging for Height Estimation and Monitoring of Single and Double Scatterers", IEEE Trans. Geosci. Remote Sens., Jan. 2009, vol. 47 (1), 224-237 ground range range elevation Satellite passes
- 14. LOW RESOLUTION DEFORMATION RESULTS
- 15. LOW RESOLUTION DEFORMATION RESULTS
- 16. LOW RESOLUTION DEFORMATION RESULTS
- 17. FULL RESOLUTION (TOMOGRAPHIC) RESULTS (Dominant scatterers)
- 18. TOMOGRAPHIC RESULTS (Dominant Scatterer)
- 19. THE LAYOVER EFFECT OVER BUILDINGS ROOF FACADE GROUND FACADE GROUND
- 20. Multiple Targets Analysis in Layover Area azimuth range
- 21. Estimated Residual Topography Single Scatterers Lower Double Scatterers Higher Double Scatterers Multiple Targets Analysis in Layover Area Detected Single Scatterers -100 +100 m azimuth range
- 22. Single and double scatterers analysis in layover Area Tomographic SAR imaging is able to resolve the interference due to multiple contribution inside the same azimuth/range pixel This interference typically occurs in urban areas where, because of the layover effect, the buildings are folded down to the ground. azimuth range
- 23. Analysis in Layover Area Detected Single Scatterers Estimated Residual Topography azimuth range -100 +100 m
- 24. Estimated Residual Topography Single Scatterers Lower Double Scatterers Higher Double Scatterers but …. Only 17 acquisitions Limited orbital tube Large incidence angle ( 44°) Multiple Targets Analysis in Layover Area -100 +100 m
- 25. Results of the Wednesday presentation with spotlight TSX data -100m 100m Amplitude image RECONSTRUCTED TOPOGRAPHY Single scatterers Double scatterers: bottom Double scatterers: upper
- 26. Results of the Wednesday presentation on TSX spotlight data
- 27. Comparison between the Edmonton and Las Vegas datasets Edmonton Number of images: 17 Imaging Mode: Stripmap Azimuth resolution: 3.3m Slant Range resolution: 1.8m Incidence Angle: 44 ° Las Vegas Number of images: 25 Imaging Mode: HRes Spotlight Azimuth resolution: 1.1m Slant Range resolution: 0.6m Incidence Angle: 36 ° slant range slant range
- 28. Estimated Residual Topography Single Scatterers Single + Lower Double Scatterers Single + Higher Double Scatterers Multiple Targets Analysis in Layover Area -100 +100 m
- 29. Multiple Targets Analysis in Layover Area Detected Double Scatterers Estimated Residual Topography - 100 +100 m Single Scatterers Single + Lower Double Scatterers Single + Higher Double Scatterers
- 30. Conclusions We have carried out an analysis of a TSX data stack over the Edmonton area (Alberta-Canada). From the monitoring viewpoint the results show the possibility to achieve a monitoring of the deformations associated with the presence of past coal seams and with the clay expansion/compaction of clays in the residential areas. Higher order analysis for the separation contributions in the Edmonton downtown areas has shown limitations which should be ascribed to the limited number of passes, to the large incidence angle. Large differences of the performances for layover separation wrt to the spotlight results achieved over another areas seem also to be associated with the acquisition mode (stripmap) FUTURE ACTIVITIES A deeper interpretation of the results wrt the clay swelling is needed Processing of more data-stacks, particular spotlights data from TSX and RADARSAT is necessary to further investigate the potentials of the tomographic technique for layover separation at X and C bands. THANK YOU
Editor's Notes
- #4: The Alberta province, in western Canada, is widely affected by natural and human-induced hazards, such as landslides or soil expansion and subsidence related to human activities (as oil extraction), that can cause severe damage to buildings and infrastructures.
- #5: Finally, surface deformation damaging buildings widely occur in the urban area due to differential swelling of clays, that are particularly susceptible to water content changes
- #6: In particular, the city of Edmonton, localized in the North Saskatchewan valley, is mainly interested by
- #7: by slope movements along the riverbanks
- #8: and subsidence associated to urban development and coal mines. Seams of coal were, in fact, extensively exploited until 1970. Subsequently, the abandoned mines, extended under both downtown and residential areas, caused collapses over the past few decades, bringing the Local Authorities to carry out mitigation measures.