PALSAR Interferometry for Geohazards Monitoring. A Comparison with C-Band and X-Band

Abstract

The Advanced Land Observing Satellite (ALOS) has been successfully launched in January 2006 and since October 2006 is regularly operating. With its three sensors it is providing radar and optical images of the earth surface for mapping, precise regional land coverage observation, disaster monitoring, and resource surveying. This work is focused on the capabilities offered by the radar L-band sensor PALSAR, in particular in the field of Interferometry and Differential Interferometry for ground deformation monitoring (i.e. volcanoes, seismic deformations, landslides and subsidence). After an introduction, we describe the algorithms that we developed to convert the operational Level-1 products to zero-Doppler coordinates and to interpolate the orbits in order to achieve the full geometric accuracy. Then, several example interferograms of different test sites are provided. The coherence is analyzed and compared with theoretical models of decorrelation and to results from sensors operating in different wavelengths like ERS Envisat (C-band) and TerraSAR-X (X-band).