Small Baseline DIFSAR Techniques for Earth Surface Deformation Analysis
Riccardo Lanari(1) and Eugenio Sansosti(1)
via Diocleziano 328,
Differential Synthetic Aperture Radar Interferometry (DIFSAR) is a
remote sensing technique that allows us to produce spatially dense
deformation maps with centimeter to millimeter accuracy. An effective
way to detect and follow the temporal evolution of deformations is via
the generation of time-series; to do this, the information available
from each interferometric data pair must be properly related to those
included in the other acquisitions, via the generation of an
appropriate sequence of DIFSAR interferograms.
In this context an innovative algorithm referred to as Small Baseline
Subsets (SBAS) approach, has been recently proposed . It relies on
the use of small baseline differential SAR interferograms (to mitigate
decorrelation phenomena) and on the application of the singular value
decomposition (SVD) method in order to link independent SAR
acquisition data sets, separated by large baselines, thus increasing
the number of data used for the analysis.
The SBAS algorithm, originally developed to investigate spatially
extended deformation phenomena has been recently extended to analyze
localized displacements that may affect, for example, small areas or
single buildings . The availability of both large and small scale
information allows us to deeply investigate the deformation behavior
of the studied zones.
In this work we present the results achieved by applying the SBAS
approach to data acquired by the European Remote Sensing (ERS)
satellites in last decade. Several test sites of scientific interest
have been considered, such as the Napoli Bay (including the Campi
Flegrei caldera and the Somma-Vesuvius volcanic complex), the Etna
volcano area and the Los Angeles zone in Southern California. The
proposed results demonstrate the effectiveness of the approach.
Moreover, it is also discussed a multi-platform DIFSAR approach for
combining ERS and ASAR ENVISAT data; this solution should allow us to
significantly extend the temporal analysis of the detected
deformations by benefiting of the future availability of ASAR data.
 P. Berardino, G. Fornaro, R. Lanari, E. Sansosti: “A new Algorithm
for Surface Deformation Monitoring based on Small Baseline
Differential SAR Interferograms”, IEEE Transactions on Geoscience and
Remote Sensing, Vol. 40, No. 11, pp. 2375-2383, November 2002.
 P. Berardino, G. Fornaro, R. Lanari, M. Manunta, M. Manzo, A. Pepe
and E. Sansosti: “A Two-Scale Differential SAR Interferometry Approach
for Investigating Earth Surface Deformations”, Proc. IGARSS, Toulouse,
France, July 2003, Vol. 2, pp. 1184 – 1186.
Keywords: ESA European
Space Agency - Agence spatiale europeenne,
observation de la terre, earth observation,
satellite remote sensing,
teledetection, geophysique, altimetrie, radar,
chimique atmospherique, geophysics, altimetry, radar,