ISSN 2070-7401 (Print), ISSN 2411-0280 (Online)
Sovremennye problemy distantsionnogo zondirovaniya Zemli iz kosmosa


Sovremennye problemy distantsionnogo zondirovaniya Zemli iz kosmosa, 2017, Vol. 14, No. 2, pp. 185-194

Radar contrast of artificial slicks at small grazing angles

A.E. Korinenko 1 , V.V. Malinovsky 1 , V.N. Kudryavtsev 2, 1 
1 Marine Hydrophysical Institute RAS, Sevastopol, Russia
2 Russian State Hydrometeorological University, Saint Petersburg, Russia
Accepted: 21.12.2016
DOI: 10.21046/2070-7401-2017-14-2-185-194
Results of field studies of radar backscatter from the sea surface covered by artificial slicks at small grazing angles are presented. The experiments were carried out in 2014–2015 at the southern coast of the Crimea near Katsiveli in the area of the Stationary oceanographic platform. A nautical X-band radar operating at horizontal polarization in transmit and receive was used. Radar was mounted on the oceanographic platform at a height of 15 m above the mean sea level. Investigations were performed for grazing angles between 6 and 1 degrees. To simulate surface contamination vegetable oil was used. It was found that specific spike-structure of radar signals at grazing angles caused by strong radar returns from large-scale breaking waves prevents discrimination of the surface slicks from the ambient area. After suppression of the speckle structure, surface slicks become well distinguishable in radar images. Analysis of statistical characteristics of the radar signal indicates that manifestation of surface slicks in radar images results from suppression of the shortest breaking waves providing radar returns. Dependencies of radar contrasts of the slick on wind speed and radar-look direction are suggested.
Keywords: radar measurements, grazing angles, breaking wind waves, surface pollution, wind waves, sea surface
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