FN Archimer Export Format PT J TI Sea‐ice detection from near‐nadir Ku‐band echoes from CFOSAT/SWIM scatterometer BT AF Peureux, Charles Longépé, Nicolas Mouche, Alexis Tison, Céline Tourain, Cédric Lachiver, Jean‐Michel Hauser, Danièle AS 1:1;2:2;3:3;4:4;5:4;6:4;7:5; FF 1:;2:;3:PDG-ODE-LOPS-SIAM;4:;5:;6:;7:; C1 Collecte Localisation Satellites, 45 avenue La Pérouse, 29 280 Plouzané, France Φ‐lab Explore Office ESRIN ,European Space Agency (ESA) Frascati ,Italy Ifremer, Univ. Brest CNRS IRD Laboratoire d’Océanographie Physique et Spatiale IUEM, 29 280 Brest , France Centre National d’Études Spatiales, Toulouse ,France Université Versailles Saint‐Quentin en Yvelines ,Sorbonne Université CNRS LATMOS Guyancourt, france C2 CLS, FRANCE ESA, ITALY IFREMER, FRANCE CNES, FRANCE UNIV VERSAILLES ST QUENTIN YVELINES UVSQ, FRANCE SI BREST SE PDG-ODE-LOPS-SIAM UM LOPS IN WOS Ifremer UMR DOAJ copubli-france copubli-europe copubli-univ-france IF 3.1 TC 9 UR https://archimer.ifremer.fr/doc/00745/85673/90814.pdf LA English DT Article DE ;SWIM;CFOSAT;sea-ice;Geophysical Model Function AB SWIM on board CFOSAT is the first spaceborne, low incidence, rotating scatterometer, aiming at measuring in near-real time ocean waves spectra. With 5 off-nadir beams at incidences between 2° and 10° plus one nadir beam, it covers the Earth in 13 days, including polar regions thanks to its polar orbit. This work aims at exploiting the SWIM data over ice regions with two objectives. An off-nadir data-based sea-ice flag is here proposed that allows, first, to eliminate sea-ice polluted echoes for improving the wave spectrum retrieval, and second, to open perspectives for application of sea-ice monitoring with near nadir Ku-band active sensors. To this end, the signature of both open water and sea-ice radar backscatter is parameterized into Geophysical Model Functions. Then, comparisons with observed profiles through a Bayesian scheme provide a probability of sea-ice presence. After comparison with both model (ECMWF-IFS) and radiometer (SSMI) derived reference data sets, the proposed flag is found to be ready for operational use. At latitudes greater than 40° in absolute value, the proposed flagging algorithm exhibits accuracies of approximately 98% for all beams compared to SSMI data. Beam to beam performances are characterized and show potential for the characterization of sea-ice at Ku band. PY 2022 PD JUL SO Earth And Space Science SN 2333-5084 PU American Geophysical Union (AGU) VL 9 IS 6 UT 000808084000001 DI 10.1029/2021EA002046 ID 85673 ER EF