Target detection method in short coherent integration time for sky wave over-the-horizon radar

In order to reduce the Doppler spread effect caused by ionospheric disturbance, sky wave over-the-horizon radar often detects ships in a short coherent integration time (CIT). In short CIT, an effective means to detect ships is clutter suppression. Through the analysis of the real data, it is found that the sea clutter has a strong correlation when the sea state is relatively stable, whether in long CIT or short CIT. To avoid estimating clutter subspace dimension and clutter cancellation times of the available methods, an adaptive clutter suppression method based on sea clutter correlation is proposed. This method does not need to estimate the parameters of the clutter, even when the Doppler frequency of the ship target is close to the sea clutter, the target can be detected. Theoretical analysis and real data processing indicate that the proposed method can detect ship target effectively.