Performance analysis of surface current extraction by HF-SAR based on first order sea echo

It is important to apply synthetic aperture technique to High Frequency Surface Wave Radar (HFSWR), and thus to implement surface current extraction by a single site, for the sake of reducing observation cost and improving efficiency. However the existing signal model of High Frequency SAR (HF-SAR) is based on theoretic point targets, and therefore the Bragg scattering effect of sea resolution cells is not considered. To solve this problem, an improved signal model of surface current extraction by HF-SAR is presented based on first order sea echo, and the effect of Bragg scattering to the azimuth echo of HF-SAR is analyzed. Then a velocity estimation algorithm is designed according to the signal features of the azimuth echo. Finally the velocity estimation performance of HF-SAR is analyzed on a specified resolution cell by Monte Carlo simulation. Simulation results show that the estimation precision of velocity and direction meets the requirements of engineering application, which indicates that it is feasibl