Manifestation of internal solitary waves on ERS SAR and SPOT images: similarities and differences

Abstract

ERS-1/2 synthetic aperture radar (SAR) and SPOT 1-3 optical images collected at the Singapore and Taiwan ground stations are used to investigate sea surface manifestations of internal solitary waves in the South China and Sulu seas. Internal waves become visible on SAR as well as on images acquired in the visible band because they are associated with sea surface roughness variations. In the past, spaceborne SAR imagery has been used extensively in studies of the dynamics of internal waves, but to a much lesser extent has visible imagery been used. In this paper the authors show that SPOT images acquired over the above mentioned ocean areas, where often cloud-free or partially cloud-free conditions are encountered, are also very useful in such studies. The similarities and differences in the internal wave signatures on SAR and optical imagery are discussed.