The characteristics of frequency correlation and group time delay of ambient noise and ship radiated-noise in the sea are studied. The theoretical and experimental results show that the frequency correlation of ship r...The characteristics of frequency correlation and group time delay of ambient noise and ship radiated-noise in the sea are studied. The theoretical and experimental results show that the frequency correlation of ship radiated-noise is much greater than that of ambient noise,and the frequency correlation of ship radiated-noise at long distance has obvious group time delay展开更多
The properties of 1(1/2)-spectrum are proved and the performances are an- alyzed. By means of the spectrum, the basic frequency component of the harmonic signals can be enhanced. Gaussian color noise and symetrical di...The properties of 1(1/2)-spectrum are proved and the performances are an- alyzed. By means of the spectrum, the basic frequency component of the harmonic signals can be enhanced. Gaussian color noise and symetrical distribution noise can be canceled. And non-quadratic phase coupling harmonic components in harmonic signal can be reduced. The ship radiated-noise is analyzed and its 7 features are extracted by the spectrum. By means of B-P artificial neural network, three type ships are classified according to extracted features. The classification results about the three type ships A, B and C are 90%, 91.3% and 85.7%. respectively.展开更多
文摘The characteristics of frequency correlation and group time delay of ambient noise and ship radiated-noise in the sea are studied. The theoretical and experimental results show that the frequency correlation of ship radiated-noise is much greater than that of ambient noise,and the frequency correlation of ship radiated-noise at long distance has obvious group time delay
文摘The properties of 1(1/2)-spectrum are proved and the performances are an- alyzed. By means of the spectrum, the basic frequency component of the harmonic signals can be enhanced. Gaussian color noise and symetrical distribution noise can be canceled. And non-quadratic phase coupling harmonic components in harmonic signal can be reduced. The ship radiated-noise is analyzed and its 7 features are extracted by the spectrum. By means of B-P artificial neural network, three type ships are classified according to extracted features. The classification results about the three type ships A, B and C are 90%, 91.3% and 85.7%. respectively.
