Oil Detection in a Coastal Marsh with Polarimetric SAR
Abstract
The NASA UAVSAR was deployed June 2010 to support Deep Water Horizon oil spill response activities expressly, oil characterization, oil detection in wetlands, and coastal resource impact detection and recovery. The UAVSAR demonstrated enhanced capability to act rapidly and provide targeted mapping responses. Our research focused on the effectiveness of high spatial resolution and fully polarimetric L-band SAR for mapping oil in wetlands, specifically within Barataria Bay in eastern coastal Louisiana (Fig.). The Bay contained numerous site observations confirming spatially extensive shoreline oil impacts, multiple UAVSAR collections, and a near anniversary 2009 collection. PolSAR oil detection relied on decomposition and subsequent classifications of the single look complex (SLC) scenes. Initial analyses results found that shoreline marsh structural damage accompanied by oil occurrence were exhibited as anomalous features on post-spill SLC flightlines but were not evident on the pre-spill SLC flightline collected in 2009. Pre-spill and post-spill Freeman-Durden (FD) and Cloude-Pottier (CP) decompositions and Wishart classifications seeded with the FD and CP classes (Wishart-FD, Wishart-CP)also highlighted these nearshore features as a change in dominate scatter. In addition, all decompositions and classifications identify a class of interior marshes within the central core of the study region that reproduce spatially extensive changes in backscatter exhibited on the pre-spill and post-spill SLC image comparisons and on all post-spill SLC images. The FD and CP decompositions revealed that the change is associated with a transform of dominant scatter from primarily surface or volume to double or even bounce. As a preponderance of evidence supports the penetration of oil-polluted waters into interior marshes, it is reasonable that marshes exhibiting different backscatter in the pre-spill and post-spill SLC renditions, identify interior marshes exposed to flushing waters containing oil. The lack of observational data within the interior marsh during the possible oil exposure and lingering uncertainty due to possible flooding in the pre-spill image, however, prevent absolute determination of whether UAVSAR detected oil occurrences in marshes far into the interior.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2011
- Bibcode:
- 2011AGUFM.U31B..02R
- Keywords:
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- 0480 BIOGEOSCIENCES / Remote sensing