Feature Analysis on the Circularity Degree of the Complex Sound Intensity in Shallow Water

In this paper, the equivalence relation between the two expressions of circularity degree vector for the complex sound intensity is derived in detail, and the correspondence between the angle component of circularity degree vector and the imaginary part of the vertical complex sound intensity is clarified through theoretical analysis. Numerical calculation and sea trial data analysis are carried out, and the results show that the amplitudes of the two parameters have similar structure distribution, almost the same "zero-crossing" position and consistent sign distribution. But only when the amplitudes of the horizontal and vertical velocity components are equal, the two parameters are equal one another.