The characteristics of frequency-time azimuth spectrum estimation by a vector hydrophone in shallow water

The impact of mechanism of interaction between the energy flow of the far-field ship noise and the near-field platform on the characteristics of frequency-time azimuth spectrum is discussed. Description of acoustic vector fields of normal modes theory is used to model the energy flows of radiated noise generated by the near-field platform. The characteristics of frequency-time azimuth spectrum are the same with the investigation by the vector hydrophone in shallow water. The azimuth of the energy flow changes with frequency. The interaction between the energy flow of the far-field ship noise and the near-field platform is simulated. The frequency-time azimuth spectrum turns up four kinds of stripes when the sound intensity of the energy flows change against each other, which is the same with the investigation of sea trial. The results of direction of arrival estimation appear inaccuracy, and vary with frequency. The main factor that affects the characteristics of frequency-time azimuth spectrum of resultant energy flow is the difference of sound pressure level. The estimation of the direction of arrival in shallow water when a number of sources exist benefits from this.