Mapping Earthquake Damage from Post-Event only VHR SAR Texture Maps: Zooming into Poor Estimation Cases

The use of EO data in earthquake contexts, especially for damage assessment purposes, has been widely proposed and a number of results have been presented after every event, mostly based on optical data and some degree of manual interpretation. Our research group tries and focus on radar data and on automatization of the damage assessment procedure by investigating the pos-sibility to use only post-event, Very High Resolution (VHR) radar data to estimate the damage level aggregated at the size of the city block. The usefulness of considering post-event only data lies in the independence from availability of pre-event VHR data, still quite scarce given the young age of meter-resolution spaceborne SAR systems like for the COSMO/SkyMed data used for these experiments. Preliminary research has highlighted some degree of connection between the damage level and the block-averaged values of some texture maps, which is probably a consequence of the different aspects in VHR SAR images between undamaged and damaged buildings. After the 2008 event in Sichuan, China, the 2009 event in L'Aquila, Italy the 2010 event in Haiti is currently being investigated and special attention is being given to the urban blocks whose damage estimates appears to diverge more from the actual situation on the ground. This paper illustrates the latest findings.