Andrea Buono

A Multipolarization Analysis of Coastline Extraction Using X-Band COSMO-SkyMed SAR Data

In this study, COSMO-SkyMed (CSK) Synthetic Aperture Radar (SAR) data, collected by the single-polarization stripmap Himage mode, are exploited for coastline extraction purposes. First, a multipolarization analysis of sea surface backscattering is undertaken using the Improved Integral Equation Method (IIEM). Then, a simple two-step approach is proposed to extract the continuous coastline from co- and cross-polarized Himage CSK SAR data. The approach is framed into two steps: 1) obtaining a binary output from the SAR image using a global threshold Constant False Alarm Rate (CFAR) detector; and 2) extracting the continuous one-pixel coastline from the binary output with a conventional Sobel edge detector. The proposed approach is verified against actual CSK SAR data and it is shown to be both effective and accurate when low-to-moderate wind conditions apply.

Iodized salt improves the effectiveness of l‐thyroxine therapy after surgery for nontoxic goitre: a prospective and randomized study

objective To investigate whether the addition of iodized salt to daily diet in thyroidectomized patients for nontoxic goitre could influence the effectiveness of nonsuppressive l‐thyroxine (L‐T4) therapy on thyroid remnant size, during 12 months’ follow‐up after thyroid surgery.

Dual-Polarimetric C- and X-Band SAR Data for Coastline Extraction

This study proposes a new metric to process dual-polarimetric coherent and incoherent synthetic aperture radar (SAR) data for coastline extraction purposes. The metric, based on the correlation between co- and cross-polarized channels, allows discriminating land from sea in an unsupervised way. Then, simple image processing is adopted to extract continuous coastline from the binary image. Experiments, undertaken on multipolarization C- (RadarSAT-2 and Sentinel-1) and X-band (Cosmo-SkyMed) SAR data collected in South of Italy together with Global Positioning System ground truth, confirm the soundness of the method which is shown to be both effective (a whole SAR scene is processed in seconds) and accurate (the mean error is less than

Polarimetric Analysis of Compact-Polarimetry SAR Architectures for Sea Oil Slick Observation

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Analysis of Full and Compact Polarimetric SAR Features Over the Sea Surface

and

A new look at the old sea oil slick observation problem: Opportunities and pitfalls of SAR polarimetry

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Model-based sea surface scattering analysis for the DWH oil spill accident case

pixels for RadarSAT-2 and CosmoSkyMed, respectively).

New generation polarimetric sars for sea oil slick observation: Full-polarimetric vs compact-polarimetric architectures

In this paper, a theoretical and experimental analysis of polarimetric synthetic aperture radar (SAR) architectures is undertaken for sea oil slick observation purposes. Reference is made to the conventional full-polarimetric (FP) SAR that is here contrasted with new-generation polarimetric SAR architectures, known as compact-polarimetric (CP) SAR. Two CP modes are considered, i.e., the hybrid-polarity and π/4 modes, whose measurements are emulated from actual L- and C-band FP SAR data. Polarimetric sea surface scattering is predicted according to an extended version of the Bragg scattering model (X-Bragg) in order to point out the differences exhibited between FP and CP SAR architectures and among CP SAR modes. Theoretical predictions are then contrasted with experiments undertaken on actual polarimetric SAR data collected over well-known oil slicks and weak-damping surfactants. Results confirm model prediction, showing that differences mainly apply when polarimetric features are estimated over slick-free sea surface using different SAR architectures, with the π/4 mode behaving closer to FP SAR. Although CP SAR architectures measure only a subset of the FP information content, they represent an interesting operational alternative for both detecting oil slicks and discriminating them from weak-damping surfactants.

Analysis of the hybrid-polarity SAR architecture for oil spill observation

In this letter, fully polarimetric (FP) and compact polarimetric (CP) synthetic aperture radar (SAR) features are investigated over the sea surface. While exhibiting similar trends, subtle differences are observed and investigated here using a new model-based approach. The model indicates that differences between the FP and CP architectures, and among the CP modes, are due to the difference in mapping between the polarimetric observables and the eigenvalues. This is verified using actual FP SAR data and emulated CP SAR measurements.

On the sensitivity analysis of the Compact-Polarimetry SAR architectures for maritime targets detection

In this study, polarimetric Synthetic Aperture Radar (pol-SAR) features are derived from full-, dual- and compact-polarimetric SAR measurements and their performance is investigated for sea oil slick observation purposes. Experiments undertaken on a RadarSAT-2 SAR scene collected over well-known oil slicks show that all the polSAR architectures allow correctly emphasizing oil slicks with respect to the surrounding sea. Full-pol and compact-pol SAR architectures allow detecting oil slicks without any adaptive thresholding, the latter is needed when dealing with dual-pol (co-co) SAR measurements. As a matter of fact, the key pitfall of pol-SAR, i.e. its limited swath, can be successfully overcame by compact-polarimetric architecture that, with respect to sea oil slick observation, exhibits performance similar to full-polarimetric SAR.