Cy. Peng et Ak. Liu, SYNTHETIC-APERTURE RADAR OBSERVATIONS OF INTERACTION OF OCEAN SWELL AND SEMIDI ISLANDS IN THE GULF OF ALASKA, International journal of remote sensing, 16(7), 1995, pp. 1249-1260
Synthetic aperture radar (SAR) images of the ocean surface can show ev
idence of the sheltering effects of barriers, such as islands, on the
incoming long ocean waves. In the presence of high background noise in
SAR images, these effects are not always observed by visual inspectio
n. As shown in this paper, they can be determined most effectively in
the spectral domain. From the ERS-1 SAR data of 17 October 1991, we no
ticed that two separate swell components almost perpendicular to each
other were incident on the Semidi Islands in the Gulf of Alaska. By sp
ectral analysis, the shadow zone associated with each wave component c
an be identified. The distribution of an equivalent diffraction coeffi
cient has been estimated at the lee of the Chowiet Island which has a
sharp tip. It has been compared to that obtained from the Sommerfeld s
olution of diffraction for a semi-infinite barrier. The SAR data shows
a similar diffraction pattern to the model solution but has a slower
fall-off into the geometric shadow zone.