Radar remote sensing from space for monitoring deformations affecting urban areas and infrastructures Riccardo Lanari IREA-CNR Napoli EGU2014, Vienna 30 April, 2014
Why Radar (SAR) Imaging from space? Active sensors: capability to "observe" during day and night Microwave sensors: capability to "observe" even in presence of clouds Coherent sensors: capability to preserve both amplitude and phase information (SAR Interferometry)
Observing with coherent systems -> DInSAR Scenario 3/2000-7/2000 S(t1) Interferogram Baseline Campi Flegrei S(t2) - λ/2 -
DInSAR Scenario (3) The 29 May 2012, 5.8 M L Emilia (North Italy) earthquake
Temporal evolution of radar satellites for Earth Observation First Generation 1992 1995 1997 1998 2001 2002 2006 2007 2010 2011 2014 ERS1 J-ERS1 ERS2 RADARSAT-1 RADARSAT-2 ENVISAT ALOS COSMO-SKYMED TERRASAR-X SENTINEL-1 Second generation ALOS-2
Advanced DInSAR technique: the Small BAseline Subset (SBAS) ERS/ENVISAT images (1992 2010) ERS ENVISAT Interferograms Ischia Campi Flegrei Mt. Vesuvio Mean deformation velocity [cm/yr] <- 0.75 > 0.75 Berardino et al., 2002, IEEE Trans. Geosci. Remote Sens. Pepe et al., 2005, IEEE Trans. Geosci. Remote Sens.
Urban deformation phenomena: the city of Rome > 0.5 Mean velocity [cm/yr] <- 0.5 Viale Giustiniano Imperatore area Zeni et al., 2011, J. Geophys. Eng. ERS/ENVISAT images (1992 2010)
Selected buildings for damage assessment Bld. 2 Building 1 Bld. 1 Building 2
DInSAR analysis on Viale Giustiniano Imperatore area P1 P2 P3 Zeni et al., 2011, J. Geophys. Eng.
Locone Lake Dam (Puglia, South Italy) ERS/ENVISAT images (1992 2007) Bonano et al., 2012, Int. J. Remote Sens.
Invasi artificiali per centrale idroelettrica Analisi SqueeSAR
COSMO-SkyMed (CSK) Constellation CSK3 CSK1 CSK2 CSK4 CSK1 8 days 1 3 days 4 days Time 16 days Sensor spatial resolution: 3 m Spatial coverage: 40 x 40 km X-band
SAR sensors : from the first to the second generation ERS: C-Band Spatial resolution: 5x20 m Revisit time: 35 days Archives: 1992-2011 Cosmo-SkyMED: X-Band Spatial resolution: 3x3 m Revisit time: 8 days Archives: 2007 - today
SAR Tomography: 3D imaging By synthesizing an antenna also in the slant height direction orthogonal to the line of sight it is possible to extend the classical 2D (azimuth-slant range) SAR imaging to 3D (azimuth-slant range-slant height). A radar scanner that can be used to analyze the vertical profile of the scattering (urban area, forest) is therefore implemented. International awards: IEEE Gesocience and Remote Sensing Letters Award 2011 Student Competition prize alla Conferenza IEEE-GRS/ISPRS JURSE 2011, Muenchen, Germania Student Competition prize alla Conferenza IEEE-GRS/ISPRS JURSE 2013, Sao Paulo, Brasile
3D reconstruction of the San Paolo Stadium (Napoli, South Italy): SAR tomography
Differential SAR Tomography: 4D imaging SAR tomography allows also monitoring displacements over the time of the reconstructed 3D point clouds. 4D imaging has been shown to overcome the performances of classical deformation monitoring methods based only on the use of the phase information, not only for what concerns the solution of the layover but also for the detection of scatterers in the absence of layover. Example of monitoring of deformation of infrastructures with the 4D Imaging technique on COSMO-Skymed data: 30 images acquired between 2010-2011.
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