Exploitation of sub-look analysis and polarimetric signatures for ship detection in PolSAR data

Synthetic aperture radar (SAR) reveals a valuable contribution to ship detection due to its all-weather and all-illumination sensing capabilities. In this paper, a new polarimetric SAR (PolSAR) ship detector is proposed that jointly exploits sub-look scattering properties of point-like scatterers (i.e. ships) and polarimetric information. The detector, which is physically based on the concepts of coherent scatterers and polarimetric signatures, consists of four main steps: first, polarimetric signatures are extracted for each sub-look image; then, the correlation coefficient (CC) between the sub-look images is calculated for varying polarization bases; ship detection is performed by setting a threshold on the resulting CC image and finally, morphological filters are applied to delineate the contour of the detected ships and automatically generate the number of targets detected. The exploitation of polarimetric information through the polarimetric signatures, on one side provides more discriminative information about target and makes the detector more robust and accurate, on the other side, it increases the computation time. The detector’s performance is verified against actual L- and C-band PolSAR datasets. Experimental results demonstrate that the proposed detector outperforms state-of-the-art ones and it results in an area under the receiver operating characteristic (ROC) curve that ranges between 0.93 and 0.95.