Ground deformation
- Stromboli volcano (Italy), 926 m above the see level (www.welt.de, 01.03.2007)
- Composition of interferogram and the amplitude image from Stromboli. Interferogram was calculated from 2 TerraSAR-X data taken from 29 Jan. and 09 Feb. 2008 with 37.5 m effective baseline and 202 m ambiguity. Phase values with the coherence bigger as 0.72 were presented.
- Composition of differential interferogram and the amplitude image from Stromboli. Differential interferogram was calculated from the same pair above and extra SRTM DEM. Differential phase with the coherence bigger as 0.72 were presented.
Observation techniques
SAR Interferometry provides the chance to detect the large scale deformation caused by volcanic activities with centimetre and even millimetre accuracy over local areas. The accuracy of InSAR is limited by temporal decorrelation of the surface and by electromagnetic path delay variations. The Persistent Scatterer Interferometry (PSI) method uses massive data stacking, selection of long term stable points and motion models in order to reduce the estimation error to the sub-millimetres level. In our workpackage, multiple satellite missions will be used in order to improve the temporal resolution.
Workplan and goals
The work will be taken out in the main test area of Fogo and at other sites such as Stromboli with lower priority. The results of the deformation analysis will be ingested into the project data base (WP3) from where they will be read an incorporated into geophysical models developed in WP5 in order to improve early warning. We expect to:
- reduce latency time and increase the sampling rate by using TerraSAR-X data with multiple incidence angles,
- discriminate sudden volcanic motion events from long term trends or rest periods,
- improve the two dimensional coverage (even in vegetated areas) to the fast motion analysis with TerraSAR-X, ALOS L-band data, and
- compare, analyse and model the decorrelation at different wavelengths (X, C, L Band).