The low-frequency line spectrum of ship-radiated noise is an important characteristic quanti?ty wiiich plays an important part in the signal detection, recognition and classification of acoustical fuze. With the decreasing of ship, especially submarine radiated acoustic energy and the increasing of ambient noise in the sea, the distance to detect targets based on using the line spectrum signal is get?ting shorter and shorter year by year. In order to denoise and detect the snip ’ s line spectrum signal submerged in ocean noise, a mathematic model of inter-scale joint distribution of wavelet coefficients for the noise and the signal was establisned, and an analytical expression of the maximum a posteriori (MAP) was deduced, on the basis of decomposing the noise and the signal by the dual tree complex wavelet transform (DT-CWl) and analyzing the inter-scale joint distribution of wavelet coefficients.
The denoised results show that the proposed algorithm can evidently weaken the continuous spectrum disturbance component and improve detecting effect of the ship ’ s line spectrum signal.
Key words
information processing technique /
line spectrum /
underwater acoustical signal processing /
signal detection
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Footnotes
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