Assessing ionospheric influence on L-band SAR data: Implications on co-seismic displacement measurements of the 2008 Sichuan Earthquake.

Daniel Raucoules (1) , Marcello de Michele (1)

1 BRGM - Bureau de Recherches Géologiques et Minières (BRGM)

Ionospheric contributions to the phase of L-band Synthetic Aperture Radar (SAR) signals put severe limitations on ground displacement measurements retrieved by either differential SAR interferometry (DinSAR) or radar amplitude image offsets. Such contributions result in an ionospheric phase screen (IPS) on the differential interferogram and in directional fluctuations in the relative position of azimuth pixels on offsets maps. In this article, we propose a procedure for estimating and removing ionospheric contributions to surface displacement measurements derived from L-band SAR data. We test the procedure on SAR data from the 28 May 2008 Sichuan Earthquake. The applied corrections allow both a clearer interpretation of the surface rupture and a more accurate measurement of the surface displacement, which has important implications in earthquake modelling based on L-band SAR data.

Mots clés: radar; interferometry; ionosphere; earthquake

Domaines: Sciences de la Terre

Daniel Raucoules, Marcello de Michele. Assessing ionospheric influence on L-band SAR data: Implications on co-seismic displacement measurements of the 2008 Sichuan Earthquake.. IEEE Geoscience and Remote Sensing Letters, 2010, 7 (2), pp.286-290. ⟨10.1109/lgrs.2009.2033317⟩. ⟨hal-00509810⟩