To detect high frequency （HF） first-order sea echo spectra contaminated with ships, ionosphere interference, and other, a new characteristic-knowledge-aided detection method is proposed. With 2-D image features in r...To detect high frequency （HF） first-order sea echo spectra contaminated with ships, ionosphere interference, and other, a new characteristic-knowledge-aided detection method is proposed. With 2-D image features in range-Doppler spectrum, the trend of first-order sea echoes is extracted as indicative information by a multi-scale filter. Detection rules for both single and splitting first-order sea echoes are given based on the characteristic knowledge combining the indicative information with the global characteristics such as amplitude, symmetry, continuity, etc. Compared with the classical algorithms, the proposed method can detect and locate the first-order sea echo in the HF band more accurately especially in the environment with targets/clutters smearing. Experiments with real data verify the validity of the algorithm.展开更多
In this paper, we first discuss the direct scattering problem for a cylindrical homogeneous clastic tube with a geometrical method, and then study the inverse problem. The heuristics of B-F procedure (Best-First searc...In this paper, we first discuss the direct scattering problem for a cylindrical homogeneous clastic tube with a geometrical method, and then study the inverse problem. The heuristics of B-F procedure (Best-First search strategy) is used. The inner radius, outer radius, sound velocitics of the tube and sound velocity of the internal medium are obtained with this heuristics.展开更多
文摘To detect high frequency （HF） first-order sea echo spectra contaminated with ships, ionosphere interference, and other, a new characteristic-knowledge-aided detection method is proposed. With 2-D image features in range-Doppler spectrum, the trend of first-order sea echoes is extracted as indicative information by a multi-scale filter. Detection rules for both single and splitting first-order sea echoes are given based on the characteristic knowledge combining the indicative information with the global characteristics such as amplitude, symmetry, continuity, etc. Compared with the classical algorithms, the proposed method can detect and locate the first-order sea echo in the HF band more accurately especially in the environment with targets/clutters smearing. Experiments with real data verify the validity of the algorithm.
文摘In this paper, we first discuss the direct scattering problem for a cylindrical homogeneous clastic tube with a geometrical method, and then study the inverse problem. The heuristics of B-F procedure (Best-First search strategy) is used. The inner radius, outer radius, sound velocitics of the tube and sound velocity of the internal medium are obtained with this heuristics.
