Advantages of recent high resolution multi-polarimetric data in flood management
Henri GIRAUD(1), Stéphanie BATTISTON(1), Stephen CLANDILLON(1), Kader FELLAH(1) and Paul DE FRAIPONT(1)
(1) SERTIT, Boulevard Sébastien Brant, BP 10413 F-67412 ILLKIRCH CEDEX, France
Over the last five years SERTIT has been requested to perform over 40 rapid mapping actions involving the use of most high and very high resolution sensors available to civil remote sensing and this in a high speed cartographic product, elaboration and publication context. Many times SERTIT has used all civilian SAR data EO sources. Within this ALOS project the potential benefits to rapid mapping is investigated, in particular the case of flood monitoring.
In fact, ALOS PALSAR has many unique features as compared to the SAR satellites in orbit now or those that were in the past, with its L-band, multi-imaging mode, varying incident angles, and multi-polarization. In this study, the focus is on the use of PALSAR data applied to flood management. Through the comparison with other SAR missions (ENVISAT/ERS, TerraSAR-X, RADARSAT-2), as regards the extraction of water surfaces, these data are tested in their appropriateness to mapping flood events.
The analysis is performed over the Moselle area, a region regularly affected by floods and where an existing database exists comprising ERS, ENVISAT, RADARSAT-1 and optical imagery as well as recent ALOS and TerraSAR-X data.
Furthermore, both technical feasibility and thematic evaluations are treated within the framework of crisis phase flood management. Throughout this project the complementarity and synergy with different radar sensors for flood rapid mapping is assessed and highlighted.
The goal of this work is to study whether water area extraction is better using multi-polarimetric radar data than using data with a single polarization. It will take the following parameters into account: band wavelength, polarization and resolution. This work falls within the framework of improving image processing techniques generally and water extraction in particular. The long-term aim is to integrate the methodological results into SERTIT’s rapid mapping service processing chains. This work is supported by the BOSS4GMES project in the framework of European Commission GMES.