Research On Underwater Target Radiated Noise Measurement Method Based On Combined Volume Array

With the continuous development of vibration and noise reduction technology,the radiated noise level of underwater target is getting lower and lower,which puts forward higher and higher requirements for radiated noise measurement technology.According to the actual situation of the test area around China and the existing radiation noise measurement technology level,this paper puts forward a broadband radiation noise measurement scheme based on the combined volume array of spiral biconical pressure volume array(middle and high frequency band)and vector sparse vertical linear array(low frequency band),and carries out the theoretical analysis and Research on the array design and broadband measurement gain calculation of the combined array.Aiming at the problem of wide-band constant beamwidth beamforming of spiral biconical pressure volume array,the spiral biconical pressure volume array is equivalent to a linear array,and the broadband constant beamwidth beamforming algorithm based on nested linear array,RSS focusing transform and Bessel series decomposition constant beamwidth beamforming algorithm based on uniform linear array are studied in this paper The performances of the three beamforming algorithms are compared and analyzed,and the performance and processing gain of the spiral biconical pressure volume array are analyzed theoretically.Aiming at the problem of low frequency radiated noise measurement of underwater target with vector sparse vertical linear array,based on the theory of isotropic noise suppression of single vector hydrophone and spatial average noise interference suppression of vertical array,the vertical spatial correlation characteristics of sea surface noise vector field are studied,and the measurement gain and array element of vector vertical array under three combinations of sound pressure and vibration velocity are analyzed theoretically The numerical results show that the measurement gain of(p+vcc)vcc combination is the largest,and that of p·p combination is the smallest.The measurement results of vector sparse vertical array in low frequency band are affected by the multi-path interference of channel interface,and the signal processing method of spatial frequency averaging is proposed.Taking sea surface interference as an example,the effect of space frequency joint processing method to suppress sea surface interference is analyzed through theoretical calculation.The results show that the noise measurement fluctuation can be effectively reduced.