Based On The Noise Characteristics Of The Target Broadband Directional Technology Research

The ship-radiated noise within a broad frequency range is the only information source of passive acoustic detection. In this thesis, the technology of target localization with war-ship's wideband radiation noise is studied.First, the method of studying the longitudinal distribution of ship's radiated noise sources based on time-frequency analyses using short-time Fourier transform was proposed. According to the analysis results and other references, the three highlight model of longitudinal distribution of the ship's radiated noise sources was proved.Then, several typical localization algorithms are introduced, and their accuracy properties are analyzed. Some traditional methods of time delay estimation are studied. Because the estimation precision is limited, adaptive FIR filter is used to estimate the time delay. It is shown that the method is effective. A micro-power consumption system is designed in chapter 5.Last, the target localization is simulated with estimated time-delay. The result is shown that this method is effective.