Oil spill characterization in the hybrid-polarity SAR domain using log-cumulants Martine M. Espeseth a , Stine Skrunes a , Camilla Brekke a , Arnt-Børre Salberg b , Cathleen E. Jones c , and Benjamin Holt c a UiT, The Arctic University of Norway, Hansine Hansens veg 14, 9019 Tromsø, Norway b Norwegian Computing Center, Gaustadalleen 23a, 0373 Oslo, Norway c Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena, CA, USA 91109 ABSTRACT Log-cumulants have proven to be an interesting tool for evaluating the statistical properties of potential oil spills in polarimetric Synthetic Aperture Radar (SAR) data within the common horizontal (H) and vertical (V) polarization basis. The use of first, second, and third order sample log-cumulants has shown potential for evaluating the texture and the statistical distributions, as well as discriminating oil from look-alikes. Log- cumulants are cumulants derived in the log-domain and can be applied to both single-polarization and multi- polarization SAR data. This study is the first to investigate the di↵erences between hybrid-polarity (HP) and full-polarimetric (FP) modes based on the sample log-cumulants of various oil slicks and open water from nine Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) scenes acquired o↵ the coast of Norway in 2015. The sample log-cumulants calculated from the HP intensities show similar statistical behavior to the FP ones, resulting in a similar interpretation of the sample log-cumulants from HP and FP. Approximately eight hours after release the sample log-cumulants representing emulsion slicks have become more similar to the open water compared to plant oil. We find that the sample log-cumulants of the various oil slicks and open water varies between the scenes and also between the slicks and open water. This might be due to changes in ocean and wind condition, the initial slick properties, and/or the di↵erence in the weathering process of the oil slicks. Keywords: Oil spill characterization, Texture, Log-cumulants, Hybrid-Polarity, SAR, UAVSAR 1. INTRODUCTION Synthetic Aperture Radar (SAR) has been widely used for oil spill monitoring. The SAR instrument is a powerful tool that provides the unique capabilities of penetrating clouds and most weather condition. Depending on the SAR mode used, large spatial coverage, high polarimetric information, and/or fine resolution can be obtained. SAR instruments can be used to detect possible oil spills, and in some cases can be used to characterize the oil spill, i.e., determine properties (dielectric, texture, shape etc.) of the oil that might help discriminate between di↵erent types of oil. The measured backscattered intensity in SAR images depends not only on the oil properties, but also on environmental conditions and sensor properties. Oil slicks dampen the waves on the sea surface and occurs as dark pixels in SAR. Therefore a major challenge to using the SAR instruments is distinguishing oil spills from natural phenomena that also dampen the waves and occur as dark pixels at the sea surface. Oil spill detection is considered possible in wind speeds from approximately 1.5 to 15 m/s, with ideal conditions from 3 - 10 m/s. 1, 2 The detectability of oil slicks is also considered to be best at incidence angle between 20 ◦ to 45 ◦ . 3 Single-polarimetric SAR o↵ers large coverage but at the cost of reduced polarimetric information. This mode has been widely used and is the currently used mode in operational oil spill monitoring. In the single channel SAR, texture features have been evaluated as input to classification methods to increase the feature space. Especially, the grey-level co-occurrence matrix (GLCM) has been used (to extract several texture features from the SAR Further author information: (Send correspondence to Martine M. Espeseth) E-mail: martine.espeseth@uit.no, Telephone: +47 776 23374 Image and Signal Processing for Remote Sensing XXII, edited by Lorenzo Bruzzone, Francesca Bovolo, Proc. of SPIE Vol. 10004, 1000414 · © 2016 SPIE CCC code: 0277-786X/16/$18 · doi: 10.1117/12.2241098 Proc. of SPIE Vol. 10004 1000414-1 Downloaded From: http://proceedings.spiedigitallibrary.org/ on 01/12/2017 Terms of Use: http://spiedigitallibrary.org/ss/termsofuse.aspx