S-RN	ship-radiated noise
FT	Fourier transform
STFT	short-time Fourier transform
WT	wavelet transform
EMD	empirical mode decomposition
IMF	intrinsic mode function
EEMD	ensemble empirical mod decomposition
VMD	variational mode decomposition
PE	permutation entropy
WPE	weighted permutation entropy
AAPE	amplitude-aware permutation entropy
RPE	reverse permutation entropy
RWPE	reverse weighted permutation entropy
MPE	multi-scale permutation entropy
FDE	fluctuation-based dispersion Entropy
OVMD	optimized variational mode decomposition
NSCC	normalized Pearson correlation coefficient
MAE	mean absolute error