AMD BML HF radar Kuroshio intrusion MPA Northern East China Sea (NECS) Research & information: general SAR SAR images Sentinel-1 Synthetic Aperture Radar UAVs accumulation-rate adaptive joint time-frequency (AJTF) decomposition airborne HF/VHF radar anthropogenic-marine-debris azimuth autocorrelation function beached-marine-litter co-evolutionary particle swarm optimization convolutional neural networks counter-flow eddy detection algorithms fully convolutional network general compact polarimetry geometric active contour model hybrid dual-polarization ideal test low-backscattering areas marine economy marine raft aquaculture