{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,1]],"date-time":"2026-02-01T04:28:06Z","timestamp":1769920086555,"version":"3.49.0"},"reference-count":29,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2021,5,9]],"date-time":"2021-05-09T00:00:00Z","timestamp":1620518400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>In the condition of ocean observation for high-resolution airborne synthetic aperture radar (SAR), sea spikes will cause serious interference to SAR image interpretation and marine target detection. In order to improve the ability of target detection, it is necessary to suppress sea spikes in SAR images. However, there is no report on sea spike suppression methods in SAR images. As a step forward, a sea spike suppression method based on optimum polarization ratio in airborne SAR images is proposed in this paper. This method is only applicable to the situation where VV and HH dual-polarized SAR data containing sea spikes are acquired at the same time. By calculating the optimum polarization ratio, this method further obtains the difference image of the panoramic area accomplishing sea spike suppression. This method is applied to a field airborne X-band SAR data, including ocean waves, oil spills and ships. The results show that the sea spikes are well suppressed, the contrast of ocean waves and the contrast of oil spills are improved, and the false alarm rate of ship detection is reduced. The discussions on these results demonstrate that the proposed method can effectively suppress sea spikes and improve the interpretability of SAR images.<\/jats:p>","DOI":"10.3390\/s21093269","type":"journal-article","created":{"date-parts":[[2021,5,10]],"date-time":"2021-05-10T02:54:58Z","timestamp":1620615298000},"page":"3269","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Sea Spike Suppression Method Based on Optimum Polarization Ratio in Airborne SAR Images"],"prefix":"10.3390","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0765-1933","authenticated-orcid":false,"given":"Yawei","family":"Zhao","sequence":"first","affiliation":[{"name":"National Key Lab of Microwave Imaging Technology, Beijing 100190, China"},{"name":"Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China"},{"name":"School of Electronics, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China"}]},{"given":"Jinsong","family":"Chong","sequence":"additional","affiliation":[{"name":"National Key Lab of Microwave Imaging Technology, Beijing 100190, China"},{"name":"Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China"},{"name":"School of Electronics, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China"}]},{"given":"Yan","family":"Li","sequence":"additional","affiliation":[{"name":"National Key Lab of Microwave Imaging Technology, Beijing 100190, China"},{"name":"Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China"},{"name":"School of Electronics, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China"}]},{"given":"Kai","family":"Sun","sequence":"additional","affiliation":[{"name":"National Key Lab of Microwave Imaging Technology, Beijing 100190, China"},{"name":"Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China"},{"name":"School of Electronics, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China"}]},{"given":"Xue","family":"Yang","sequence":"additional","affiliation":[{"name":"National Key Lab of Microwave Imaging Technology, Beijing 100190, China"},{"name":"Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China"},{"name":"School of Electronics, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China"}]}],"member":"1968","published-online":{"date-parts":[[2021,5,9]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"71","DOI":"10.1109\/JOE.2012.2210800","article-title":"On the COSMO-SkyMed PingPong mode to observe metallic targets at sea","volume":"38","author":"Nunziata","year":"2013","journal-title":"IEEE J. Ocean. Eng."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"4650","DOI":"10.1109\/TGRS.2015.2405577","article-title":"Analysis of X-band SAR sea-clutter distributions at different grazing angles","volume":"53","author":"Fiche","year":"2015","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_3","first-page":"5644","article-title":"SAR image detection of sea targets based on two-step CFAR detector of KK distribution","volume":"19","author":"Song","year":"2019","journal-title":"J. Eng."},{"key":"ref_4","unstructured":"Skolnik, M.I. (2008). Radar Handbook, McGraw-Hill. [3rd ed.]."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"291","DOI":"10.1109\/JOE.1984.1145638","article-title":"A deterministic, coherent, and dual-polarized laboratory study of microwave backscattering from water waves, Part I: Short gravity waves without wind","volume":"9","author":"Kwoh","year":"1984","journal-title":"IEEE J. Ocean. Eng."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"27","DOI":"10.1109\/8.655448","article-title":"Measurement and classification of low-grazing-angle radar sea spikes","volume":"46","author":"Liu","year":"1998","journal-title":"IEEE Trans. Antennas Propag."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"C02003","DOI":"10.1029\/2007JC004319","article-title":"Analysis of radar sea return for breaking wave investigation","volume":"113","author":"Hwang","year":"2008","journal-title":"J. Geophys. Res."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Kulemin, G.P. (2001, January 19). Spike characteristics of radar sea clutter for extremely small grazing angles (Part 2). Proceedings of the Laser Radar Technology and Applications VI, Orlando, FL, USA.","DOI":"10.1117\/12.440122"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"4556","DOI":"10.1109\/TGRS.2013.2239112","article-title":"Sea-spike detection in high grazing angle X-band sea-clutter","volume":"51","author":"Rosenberg","year":"2013","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1136","DOI":"10.1109\/TAES.2017.2667558","article-title":"Target detection in sea-clutter using stationary wavelet transforms","volume":"53","author":"Duk","year":"2017","journal-title":"IEEE Trans. Aerosp. Electron. Syst."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1002","DOI":"10.1109\/TGRS.2013.2246574","article-title":"Detection and extraction of target with micromotion in spiky sea clutter via short-time fractional Fourier transform","volume":"52","author":"Chen","year":"2014","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_12","unstructured":"Sun, H., and Wan, X. (2020, January 19\u201321). Research on the sea spike suppression based on range domain characteristics of relatively high resolution radar. Proceedings of the International Symposium on Electronic Information Technology and Communication Engineering, Jinan, China."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"48","DOI":"10.1049\/iet-rsn.2009.0247","article-title":"Target detection in high-resolution sea clutter via block-adaptive clutter suppression","volume":"5","author":"Shi","year":"2011","journal-title":"IET Radar Sonar Navig."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"809","DOI":"10.1109\/LGRS.2019.2935262","article-title":"Detection of small floating targets on the sea surface based on multi-features and principal component analysis","volume":"17","author":"Gu","year":"2019","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"5307","DOI":"10.1109\/TGRS.2012.2234128","article-title":"The radiometric measurement quantity for SAR images","volume":"51","author":"Schwerdt","year":"2013","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_16","unstructured":"Yuan, L., Ge, J., Jiang, K., and Wang, Y. (2009, January 26\u201330). Research on efficient calibration techniques for airborne SAR systems. Proceedings of the 2nd International Asia-Pacific Conference on Synthetic Aperture Radar, Xi\u2019an, China."},{"key":"ref_17","unstructured":"Schreiber, F.M., Angelliaume, S., and Gu\u00e9rin, C.A. (2020). Modeling the polarization ratio in the upper microwave band for sea clutter analysis. IEEE Trans. Geosci. Remote Sens., 1\u201313."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"193","DOI":"10.1109\/TGRS.2019.2935343","article-title":"The Doppler spectrum of the microwave radar signal backscattered from the sea surface in terms of the modified Bragg scattering model","volume":"58","author":"Karaev","year":"2020","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_19","unstructured":"Holecz, F., Meier, E., Piesbergen, J., Wegmuller, U., and Nuesch, D. (1994, January 8\u201312). Radiometric calibration of airborne SAR imagery. Proceedings of the 1994 IEEE International Geoscience and Remote Sensing Symposium, Pasadena, CA, USA."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"518","DOI":"10.1109\/TGRS.2003.808836","article-title":"An L-band geophysical model function for SAR wind retrieval using JERS-1 SAR","volume":"41","author":"Shimada","year":"2003","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"6046","DOI":"10.1002\/2014JC010173","article-title":"Quad-polarization SAR features of ocean currents","volume":"119","author":"Kudryavtsev","year":"2014","journal-title":"J. Geophys. Res. Oceans"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"4929","DOI":"10.1109\/JSTARS.2016.2587840","article-title":"Wave breaking in slicks: Impacts on C-band quad-polarized SAR measurements","volume":"9","author":"Hansen","year":"2016","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"2313","DOI":"10.1109\/TGRS.2016.2641682","article-title":"Facet-based investigation on microwave backscattering from sea surface with breaking waves: Sea spikes and SAR imaging","volume":"55","author":"Li","year":"2017","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"9792","DOI":"10.1029\/JC088iC14p09792","article-title":"L band SAR ocean wave observations during MARSEN","volume":"88","author":"Jain","year":"1983","journal-title":"J. Geophys. Res."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"863","DOI":"10.1109\/TGRS.1986.289701","article-title":"Numerical simulation of synthetic aperture radar image spectra for ocean waves","volume":"GE-24","author":"Lyzenga","year":"1986","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1958","DOI":"10.1109\/TGRS.2014.2351417","article-title":"Comparing near-coincident C- and X-band SAR acquisitions of marine oil spills","volume":"53","author":"Skrunes","year":"2015","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"071598","DOI":"10.1117\/1.JRS.7.071598","article-title":"Target detection in synthetic aperture radar imagery: A state-of-the-art survey","volume":"7","author":"McGuire","year":"2013","journal-title":"J. Appl. Remote Sens."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"184","DOI":"10.1109\/LGRS.2016.2633548","article-title":"Ship detection for complex background SAR images based on a multiscale variance weighted image entropy method","volume":"14","author":"Wang","year":"2017","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"4209","DOI":"10.1109\/TGRS.2018.2828833","article-title":"Ship wake components: Isolation, reconstruction, and characteristics analysis in spectral, spatial, and TerraSAR-X image domains","volume":"56","author":"Sun","year":"2018","journal-title":"IEEE Trans. Geosci. Remote Sens."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/9\/3269\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T05:58:30Z","timestamp":1760162310000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/9\/3269"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,5,9]]},"references-count":29,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2021,5]]}},"alternative-id":["s21093269"],"URL":"https:\/\/doi.org\/10.3390\/s21093269","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,5,9]]}}}