Ship detection with short coherent integration time in over-the-horizon radar

To realize the ship detection with short coherent integration time (CIT) is an operational requirement for skywave over-the-horizon radar (OTHR). However, short CIT and the resulting low Doppler resolution cannot separate the ship from the close powerful ocean clutter. To resolve this problem, Fourier transform based clutter cancellation is proposed as well as some super-resolution spectral estimation techniques. In this paper, we still use a clutter subtraction scheme but the clutter parameter estimation is improved by analyzing the Fourier phase information. As a result, the estimation accuracy is enhanced and better cancellation performance may be achieved, which to some extent will decrease the power and spreading of clutter residue and benefit the ship visibility and identification.