On The TerraSAR-X Dual-Mode For Oil Slick Observation
Domenico Velotto(1), Maurizio Migliaccio(2), Ferdinando Nunziata(2) and Susanne Lehner(1)
(1) DLR, Münchner Straße 20, 82234 Weßling, Germany
(2) Università di Napoli Parthenope, Centro Direziale, isola C4, 800143 – Napoli, Italy
The TerraSAR-X satellite provides high-quality, multi-mode X-band SAR-data of the ocean surface for scientific research and associated applications. Polarimetric SAR data are able to give additional information, which can be successfully exploited to observe the Earth surface, once a proper electromagnetic model is available. Using the dual-mode TerraSAR-X capability we test this kind of data because is operationally important for oil spill observation. For the purpose of this study Single Look Slant Range Complex (SSC) Dual Polarization StripMap (SM) TerraSAR-X products are investigated.
The processing accomplished consists in looking at the different polarimetric scattering mechanisms expected with and without oil slicks. The electromagnetic model applied is based on the phase difference between the complex HH and VV channels, the co-polar phase difference, called CPD, which has been demonstrated to be suitable both to observe sea oil spills and distinguish them from biogenic look-alikes in C-band SAR data ,.
Experiments, accomplished over a meaningful set of SSC HH/VV TerraSAR-X data show the consistence of the CPD model for both observing sea oil slicks and distinguishing them from weak-damping look-alikes. Moreover, it is shown that the standard deviation of the CPD probability density function (pdf) contains the key information.
The importance of this study is twofold. On one hand, it shows that TerraSAR-X dual-polarized SAR data are suitable for physically based sea oil slick observation. On the other hand, it demonstrates for the first time that X-band polarimetric data can be successfully employed to observe oil slicks, once properly modelled.
 M. Migliaccio, F. Nunziata, A. Gambardella, “On The Copolarised Phase Difference for Oil Spill Observation”, Int. Journal of Remote Sensing, vol. 30, n. 6, pp. 1587-1602, 2009.
 F. Nunziata, A. Gambardella and M. Migliaccio, “On the Mueller Scattering Matrix for SAR Sea Oil Slick Observation”, IEEE Geosci. and Remote Sensing Letters, vol. 5, n. 4, pp. 691-695, 2008.