The Simulation Of Ship Radiated Noise Considering Multi-resource And The Realization Of Output

Ship-radiated noise within quite a broad frequency range is the only information source of passive acoustic detection, and the power spectrum characteristics of the noise at different sections of a ship are different. At short distance, a ship should not be considered to be a dot target, but a volume target with longitudinal size. It is possible to reconfiguration each different part of ship-radiated noise.The main studies of this dissertation are to reconfigure the time-frequency domain feature, the time domain wave and to simulate the through processes, considering multi-radiated sources of the ship-radiated noise. The main work is as follows:Study the longitudinal distribution of ship-radiated noise source based on time-frequency analysis of short-time Fourier transform and the power spectrum of different position. According to the analysis, the three highlight model of longitudinal distribution of ship-radiated noise sources was proved: the section between the stern and the middle way of ship, midway of ship, and stern. According to the analysis results, the mathematics model of the ship-radiated noise including the arithmetic of reconfiguring the ship noise with continuous spectrum and line spectrum. A method for generating a random time sequence having both specified amplitude probability distribution and desired power spectrum features is applied in this paper. Simulate the time domain signal of ship-radiated noise as a volume target. Simulate the effect characteristic in different position of ship-radiated noise based on the time domain data. Compare between simulation result and spectrum of ship. At last, the sea noise background was analyzed and simulated.