APPROACHES CHARACTERIZATION:POLSAR-BASED...

SEAOILSLICKDETECTION,CLASSIFICATIONAND

CHARACTERIZATION:POLSAR-BASEDAPPROACHES

A. Buono♣, F. Nunziata♣♦, X. Li♠, Y. Wei♦, X. Ding♦

andrea.buono@uniparthenope.it

♣Dipartimento di Ingegneria, Universita degli Studi di Napoli “Parthenope”, Napoli, Italy♠NOAA/NESDIS, Global Science & Technology, College Park, MD 20740, USA♦Shanghai Ocean University, College of Marine Science, Shanghai 201306, China

MOTIVATIONSMarine oil pollution is a hot scientific and environmental topic. Oil sources are very different and, therefore, the observation systems should satisfy differentrequirements [1]. Official statistics state that ≈ 70% of the overall oil released at sea is due to human activities related to petroleum consumption: theyrepresent random and frequent sources of small-size oil spills. A large amount of oil spills is also related to petroleum extraction and transportationactivities (≈ 10% and 20%, respectively): the former represent sources of crude oil and refined products that lead to well-located and highly variablein nature and size (i.e., natural oil seepages) oil spills, while the latter include both small-size frequent oil spills due to operational activities and largeaccidental disasters (i.e., the Deepwater Horizon case). Accordingly, a sea oil pollution observation system should meet different measurements:

POLARIMETRIC SAR-BASED APPROACHESPolarimetric SAR-based approaches for sea oil slick monitoring rely on a physical rationale based on the sea surface Bragg scattering model. Underlow-to-moderate sea state regimes and for intermediate incidence angles, the slick-free sea surface, as well as weak-damping look-alikes (ships’ wakes,biogenic pollutants, etc.), is characterized by the almost deterministic Bragg scattering, while a strong departure applies over strong damping oil slicks[2]. Such departure can be reliably estimated using a large set of polarimetric features that can be classified according to the kind of available SAR data:

DUAL-POL SARWhen DP SAR measurements are available (i.e.,two scattering amplitudes), coherent co-polarizeddata, i.e., HH-VV channels, are needed. Thresh-olding algorithms have to be applied for oil de-tection purposes. As an example, the σ approachresults are shown [2]:

COMPACT-POL SARWhen CP SAR measurements are available, (i.e.,backscattered waves coherently received in theH-V basis once circularly (HP) or slant linearly(π/4) polarized waves are transmitted), thresh-olding algorithms can be avoided using µw orsin(2χ). HP Pw approach results are shown [2]:

QUAD-POL SAR

When QP SAR measurements are available (i.e.,the full scattering matrix), the maximum amountof physical information on the observed scene canbe exploited. Logical binary outputs can be au-tomatically obtained using µ. NPH-based char-acterization results are shown [2,3]:

REFERENCES[1] Fingas, M. F. and Brown, C.E., 2015 , Handbook of Oil Spill Science and Technology: Oil Spill Remote Sensing. Wiley, pp. 313-356.

[2] Migliaccio, M. Nunziata, F. and Buono, A., 2015, A Review on SAR Polarimetry for Sea Oil Slick Observation. International Journal Remote Sensing, in print.[3] Migliaccio, M. and Nunziata, F., 2014, On the Exploitation of PolSAR Data to Map Damping Properties of the DWH Oil Spill. IJRS, 35, no. 10, pp. 3499-3519.