Extraction of sea surface current pattern in Bab al-Mandab strait using radar sentinel-1 C-band SAR image

Abstract EN

This paper presents the results of sea surface current pattern (velocity and direction) extraction in Bab Al-Mandab Strait in the south east part of Yemen.

The Sentinel-1 (S-1) C-band Synthetic Aperture Radar (SAR) image used in this study is Level-1 (IW) Ground Range Detected (GRD) single mode product.

It was acquired on September 8th 2016 at 21:25:12 in VV polarization.

The pixel spacing for both range and azimuth is 10 m.

The incidence angles ranged between 30.86° at the near range to 36.59° at the far range.

Four experimental areas were randomly selected to validate modeled results of the sea surface current patterns extracted from the Sentinel-1 SAR image.

The length of each subset image is (512 X 512) pixels across the range resolution.

Three different steps were used in this study to extract sea surface current patterns in the study area.

The first step is the extraction of distribution of radar cross section.

The second step is the calculation of Doppler frequency shift in order to extract the SAR spectra.

The final step is to find the sea surface current rose diagram to verify the speed and direction.

This study emphasizes the importance of the Doppler frequency by which to extract the sea surface current patterns from SAR images.