Retrieval of a real-time sea surface vector field from SAR Doppler
centroid:2. on the radial velocity
Abstract
The concept of radial velocity is proposed for high frequency (HF) radar
for sea surface current measurement. However, in a spaceborne synthetic
aperture radar (SAR) system, the meaning of this concept has changed
greatly. Through the evidence and analysis presented in this paper, the
radial velocity of the sea surface observed via spaceborne SAR is
revealed from the projection of the satellite’s velocity at different
points along the range direction, and its distribution on the image
presents a strip-like texture, which is very different from the central
radial distribution on the velocity image measured via HF radar. The
retrieved sea surface velocity field does not exhibit any radial
characteristics, and its value is solely the magnitude of the sea
surface velocity.