Spectrum characteristics for internal wave signals of a self-propelled model.

Internal waves induced by an underwater self-propelled body expose its existence by changing the sea surface roughness. This study employs short-time Fourier transform to perform the time–frequency analysis on the internal wave signal captured in the experiments. Some key characteristics of the underwater self-propelled body are obtained through the spectrum analysis of the internal wave wake signal. Moreover, the influence of the interaction between the momentums induced by the propulsion and drag force is discussed. The results show that the action of the self-propelled body has varying degrees of influence on the symmetry and spatial distribution of the spectrum characteristics of the signal. [ABSTRACT FROM AUTHOR]