Abstract
Abstract. This research work investigates the efficacy of the Stanford Method for Persistent Scatterer Interferometry (StaMPS) in measuring the surface deformation over the L'Aquila region, Italy just before an event of earthquake of magnitude Mw 6.3 by using seven descending Envisat C-Band ASAR images. The results show that the StaMPS technique successfully extracted sufficient number of Persistent Scatterers (PS) to derive a one dimensional (1D) time series displacement map which shows the deformation rates up to 59 mm/year in the satellite Line of Sight (LOS) direction and 50.8 mm/year in the direction opposite to the satellite LOS. Further, several deformation gradients are also observed from this map which indicate the occurrence of multiple crustal movement mechanism. Another dataset of 14 ASAR images is processed covering a time period before and after the earthquake in the study area to validate the results obtained by the previous dataset. We observed that the generated displacement map follows the deformation characteristics of the earlier displacement map in terms of magnitude and surface movement. We conclude that the generated displacement maps validate the presence of a normal fault mechanism with a tectonic process stretching in a NW-SE direction as predicted by earlier research studies.
Highlights
SAR interferometry (InSAR) is a technique for measuring surface deformation by generating phase difference images known as interferograms using two or more images of the same area acquired at slightly different look angles
The approach is successful in finding Persistent Scatterers (PS) pixels in both urban and nonurban areas, which makes it applicable in areas covered by forests and vegetation as well, as it is able to find low amplitude phase stable pixels in those areas, making it more preferable than other PS-InSAR software known as DePSI, which is successful in detecting deformation in urban areas but not able to detect deformation in nonurban areas (Sousa, 2010)
The displacement plot obtained by using 14 SLC images gives a representation of the deformation pattern in the study area as we find that the north-west and south-east regions with respect to the earthquake epicenter exhibit a displacement of nearly equal magnitude in opposite directions which commensurate the normal fault mechanism
Summary
SAR interferometry (InSAR) is a technique for measuring surface deformation by generating phase difference images known as interferograms using two or more images of the same area acquired at slightly different look angles. These interferograms are used to estimate the surface deformation using the relationship between phase, slant range, satellite position and acquisition time. The approach is successful in finding PS pixels in both urban and nonurban areas, which makes it applicable in areas covered by forests and vegetation as well, as it is able to find low amplitude phase stable pixels in those areas, making it more preferable than other PS-InSAR software known as DePSI, which is successful in detecting deformation in urban areas but not able to detect deformation in nonurban areas (Sousa, 2010). The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XL-8, 2014 ISPRS Technical Commission VIII Symposium, 09 – 12 December 2014, Hyderabad, India application to the study area, the results obtained along with discussions and conclusions
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