“…The methods used for ship classification with SAR images mainly focus on feature selection and optimized classifier techniques [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 ]. Currently, commonly used features are (1) geometric features, such as ship length, ratio of length to width, distribution of scattering centers, covariance coefficient, contour features [ 11 ], and ship scale; and (2) scattering features, such as 2D comb features [ 7 ], local radar cross section (RCS) density [ 1 ], permanent symmetric scatterers [ 12 ], and polarimetric characteristics [ 13 ].…”