Internal wave SAR detection method based on compressive sensing and EMD

Spaceborne synthetic aperture radar (SAR) can retrieve the internal wave from detection backscatter of sea surface. Compressive sensing (CS) is adopted for wave sparse sampling to solve the huge amount of echo data. However, in many practical situations, the sparsity of ocean internal wave is corrupted by the influence of noise which causes the reconstructed signal amplitude loss in CS. To solve this problem, an approach of signal reconstruction based on empirical mode decomposition (EMD) is presented. Firstly, the sparsity is enhanced and the noise level is reduced by EMD while maintenance the original signal as possible. Then reconstructed signal by employing the algorithm of orthogonal matching pursuit. Reconstruction results show that the proposed method can effectively suppress noise and improve the sparsity of the signal. Our results also demonstrate that the magnitude loss of the reconstructed signal is reduced, and the convergence speed of orthogonal matching pursuit algorithm is accelerated.