Gulf Oil Spill
The UAVSAR Gulf Oil-Spill Campaign, 2010-2012
by Cathleen E. Jones, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
In May 2010, as oil from the Deepwater-Horizon (DWH) rig blowout that occurred on April 20th continued to spread across the Gulf of Mexico and with the specter of widespread impact to sensitive ecosystems along large portions of the United States (U.S.) Gulf Coast looming large, the National Aeronautics and Space Administration (NASA) made the decision to deploy several of its newest, most technologically advanced, airborne science instruments to the area to support response activities and scientific studies of the oil slick and its impact to the region. One of these instruments was the Jet Propulsion Laboratory (JPL) Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR), an L-band (23.8-cm wavelength) radar that has been operating since 2009 for Polarimetric SAR (POLSAR) and Differential Radar Interferometry (DInSAR) studies supporting a wide variety of science and application disciplines. The goals of the Gulf Oil-Spill Campaign included characterizing oil in the slick in open waters; tracking oil ingress into coastal waterways and marshlands; monitoring impact and recovery of oil-affected wetlands; and understanding how the instrument could support emergency responders in future disasters. The campaign was started with the intention of repeating the collections as necessary to track ecosystem recovery in the years following the spill. Now, 2 years after the disaster, NASA is still committed to these science goals, supporting yearly science flights over areas along the Louisiana and Mississippi coasts to monitor impact and recovery of wetlands most-heavily affected by the DWH spill. Pre-spill data over parts of the impacted area were acquired in 2009 and early 2010, extensive data were acquired in June 2010 during the spill, and post-spill, repeat-track data were acquired in June 2011 and July 2012.
The first deployment of the UAVSAR Gulf Oil-Spill Campaign took place on 22-23 June 2010, at a time when the DWH well remained uncapped and it was unknown how much of the Gulf Coastline would ultimately be affected by oil from the spill. The campaign was planned to image as much of the Gulf Coastline as possible to provide a baseline data set to compare post-oiling acquisitions in the most significantly-affected coastal areas of the U.S. In 2010, UAVSAR collected quad-polarization data along nearly 5,500 km of flight lines covering an area of ~120,000 km2 (Figure 1a). Most of the U.S. Gulf of Mexico coastline, extending from the Florida Keys to Corpus Christi, Texas, was imaged, including extensive inland coverage of the southern Louisiana wetlands. Parts of the main slick that formed near the DWH-rig site (Figure 1b) and areas of the Gulf of Mexico extending from the rig site to the Louisiana coast and eastward to near Pensacola, Florida, were imaged in three flight lines. Most of the flight lines over Louisiana, Texas, and the Mississippi barrier islands were reacquired in June 2011 and July 2012. The anniversary collections match low-tide conditions and seasonal vegetation state in the heavily-impacted Barataria Bay, Louisiana. This body of data is available to researchers through the ASF DAAC.
Sample images from UAVSAR data collected along the Gulf Coast are shown in Figures 2 and 3. Figure 2 shows multipolarization images of Petit Bois Island, Mississippi, acquired in June 2010 and 2011, along UAVSAR flight line MSisln_27105. UAVSAR-POLSAR data is available covering most of the barrier islands bordering the southern U.S. states. Figure 3a shows a multipolarization image of an area centered on Bay Jimmy to the northeast of Barataria Bay that contained oil-contaminated waters. A close-up of an island in the area (Figure 3b) shows reduced co-polarized returns along oiled shorelines, making these areas show up as green (HV dominant) in the image.
Two years after the first data in this campaign were collected, UAVSAR low-noise, fine spatial resolution (7-m multilooked products) and full polarization (HH, VV, and HV) capability enabled advances in oil-slick detection and characterization; oil extent mapping in coastal areas and ecosystem impact; and marine surveillance and applications of SAR for emergency response. The data collected in this campaign are of value both for studies specific to the oil spill, and as a baseline image set of the Gulf of Mexico region for future efforts to use UAVSAR data to study the ecology, geology, and anthropogenic changes in the area.
©2012 California Institute of Technology. Government sponsorship acknowledged. This work is performed at JPL, California Institute of Technology, under contract with NASA.