Vol. 5, No. 2, 199-207, 2006

Abstract
A series of ASAR images with alternating polarization was acquired over Peter the Great Bay, Japan Sea in 2003-2005. A combination of horizontal-horizontal (HH) and vertical-vertical (VV) polarization was used with two different mean incidence angles q = 18.3° and 22.5°. Additionally, the same scenes were sensed on 23 September 2004 by ERS-2 SAR with a delay of about 30 min after the ASAR acquisition. The main aim was to study the polarimetric signatures of the sea surface caused by the oceanic dynamic phenomena as well as by natural and anthropogenic slicks for later use for their detection and classification. During the ASAR and SAR data acquisitions, ground-truth measurements of the sea surface temperature, wind speed and direction as well as polarization images of the sea surface recorded by a polarization video system were arranged at POI Marine Stations and at several coastal points. Wind fields were also retrieved from the SAR images using the CMOD-4 scatterometer algorithm. As a rule, the wind speed during the satellite observations did not exceed 7 m/s so that radar signatures of slicks, eddies, currents, and internal waves were revealed on the SAR images. The HH and VV radar cross-sections s_oHH and s_oVV computed from ASAR data decreased with q and the polarization ratio P = s_oVV/s_oHH increased. Variations of P in the area around the slicks reached 2-4 dB which calls for further investigations.

ISSN 1729-3782