Installation and data analysis of a small network of SAR corner reflectors in Fogo, Cape Verde

摘要

Since early ninety’s Synthetic Aperture Radar Interferometry (InSAR) has been exploited forgeophysical applications. InSAR technique is capable to capture information on surface deformation and canbe a useful tool for monitoring active seismic and volcanic areas. Despite the capability of SAR sensors tooperate in all weather and day/night conditions, SAR signal is affected by different source of noise (e.g.water vapour or instrumental noise) [Hanssen, 2001]. These disturbing sources affect the accuracy of InSARdeformation map, especially for time series analysis, and the quality control of InSAR measurements, eitherstandard differential interferometry and Persistent Scatterers Interferometry (PSI), is not an easy task. Afruitful solution is represented by the adoption of passive Corner Reflectors (CRs). CRs can provide pointmeasurements with high level of confidence with sub-centimeter accuracy [Marinkovic et al, 2007], thanksto their high backscattered signal value, and representing strong persistent scatterers to be used forcalibrating and validating SAR (from InSAR and PSI technique) deformation map. Indeed, CRs can maintaintheir interferometric phase stable during time. Additionally, CRs can also be exploited to calibrate theamplitude SAR signal, and to provide reference points for geocoding purposes.Here we present the design, realization and installation of a small CRs network on the Fogo Volcanoisland, Cape Verde. This activity has been done in the framework of the European project MIAVITA,MItigate and Assess risk from Volcanic Impact on Terrain and human Activities.