Experimental L-Band Airborne SAR for Oil Spill Response at Sea and in Coastal Waters

Abstract

Satellite synthetic aperture radar (SAR) is frequently used during oil spill response efforts to identify oil slick extent, but suffers from the major disadvantages of potential long latency between when a spill occurs and when a satellite can image the site and an inability to continuously track the spill as it develops. We show using data acquired with the Uninhabited Aerial Vehicle SAR (UAVSAR) instrument how a low noise, high resolution, L-band SAR could be used for oil spill response, with specific examples of tracking slick extent, position and weathering; determining zones of relatively thicker or more emulsified oil within a slick; and identifying oil slicks in coastal areas where look-alikes such as calm waters or biogenic slicks can confound the identification of mineral oil spills. From these key points, the essential features of an airborne SAR system for operational oil spill response are described, and further research needed to determine SAR’s capabilities and limitations in quantifying slick thickness is discussed.

Oil Slick Characterization Using a Statistical Region-Based Classifier Applied to UAVSAR Data

“…Previous research [2,5,7] indicated a relationship between the oil slick thickness and the damping effect on the sea surface roughness. Thicker layers cause more damping of the capillary and gravity-capillary waves, and hence appear darker than thinner layers of oil in SAR imagery.…”

“…During emergency response, the oil containment and recovery are the main cleanup operations with potential to minimize these impacts. The thickness of the oil slick has a significant effect on the recovery efficiency rates, being higher over the thicker layers [1,2]. Synthetic Aperture Radars (SAR) data are most frequently used by operational oil spill surveillance service providers to detect and monitor oil slicks on the sea surface.…”

“…Synthetic Aperture Radars (SAR) data are most frequently used by operational oil spill surveillance service providers to detect and monitor oil slicks on the sea surface. Within the microwave region of the electromagnetic spectrum, oil slicks and look-alikes dampen the sea surface roughness and are detected as low backscatter regions [1][2][3][4][5][6].…”

“…The potential of the polarimetric SAR (PolSAR) data in full, dual, and compact polarization modes was indicated to distinguish petrogenic from biogenic oil slicks and other look-alikes in some circumstances [8][9][10]. However, methodologies able to characterize oil slicks by extracting additional information regarding the thickness variations within the slicks have been less explored until recently [2,5,[11][12][13][14].…”

Oil Spill Segmentation in Ship-Borne Radar Images with an Improved Active Contour Model

“…The shortcoming of satellite-borne remote sensing is that it cannot monitor spills in real-time. With the rapid development of unmanned aerial vehicles (UAV), airborne radar detection technology has progressed quickly [15][16][17]. However, UAVs require favorable weather.…”