FN Archimer Export Format PT J TI Guided Unsupervised Learning by Subaperture Decomposition for Ocean SAR Image Retrieval BT AF Ristea, Nicolae-Cătălin Anghel, Andrei Datcu, Mihai Chapron, Bertrand AS 1:1;2:1;3:2;4:3; FF 1:;2:;3:;4:PDG-ODE-LOPS-SIAM; C1 Research Center for Spatial Information (CEOSpaceTech) and the Department of Telecommunications, University Politehnica of Bucharest, Bucharest, Romania Research Center for Spatial Information (CEOSpaceTech), University Politehnica of Bucharest, Bucharest, Romania Laboratoire d'Ocanographie Physique et Spatiale (LOPS), Plouzané, Ifremer, France C2 UNIV POLITEHNICA BUCHAREST, ROMANIA UNIV POLITEHNICA BUCHAREST, ROMANIA IFREMER, FRANCE SI BREST SE PDG-ODE-LOPS-SIAM UM LOPS IN WOS Ifremer UMR copubli-europe IF 8.2 TC 3 UR https://archimer.ifremer.fr/doc/00840/95206/102904.pdf LA English DT Article DE ;Radar polarimetry;Image retrieval;Doppler effect;Synthetic aperture radar;Transformers;Task analysis;Sea surface;Doppler centroid estimation (DCE);image retrieval;ocean imagery;remote sensing (RS);subapertures decomposition;synthetic aperture radar (SAR);unsupervised learning AB A spaceborne synthetic aperture radar (SAR) can provide accurate images of the ocean surface roughness day-or-night in nearly all-weather conditions, being a unique asset for many geophysical applications. Considering the huge amount of data daily acquired by satellites, automated techniques for physical features extraction are needed. Even if supervised deep learning methods attain state-of-the-art results, they require a great amount of labeled data, which are difficult and excessively expensive to acquire for ocean SAR imagery. To this end, we use the subaperture decomposition (SD) algorithm to enhance the unsupervised learning retrieval on the ocean surface, empowering ocean researchers to search into large ocean databases. We empirically prove that SD improves the retrieval precision with over 20% for an unsupervised transformer autoencoder network. Moreover, we show that SD brings an important performance boost when Doppler centroid images are used as input data, leading the way to new unsupervised physics-guided retrieval algorithms. PY 2023 SO Ieee Transactions On Geoscience And Remote Sensing SN 0196-2892 PU Institute of Electrical and Electronics Engineers (IEEE) VL 61 IS 5207111 UT 000996488200015 DI 10.1109/TGRS.2023.3272279 ID 95206 ER EF