{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,31]],"date-time":"2026-01-31T07:58:05Z","timestamp":1769846285869,"version":"3.49.0"},"reference-count":17,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2018,4,10]],"date-time":"2018-04-10T00:00:00Z","timestamp":1523318400000},"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>Spaceborne synthetic aperture radar (SAR) missions operating at low frequencies, such as L-band or P-band, are significantly influenced by the ionosphere. As one of the serious ionosphere effects, Faraday rotation (FR) is a remarkable distortion source for the polarimetric SAR (PolSAR) application. Various published FR estimators along with an improved one have been introduced to solve this issue, all of which are implemented by processing a set of PolSAR real data. The improved estimator exhibits optimal robustness based on performance analysis, especially in term of the system noise. However, all published estimators, including the improved estimator, suffer from a potential FR angle (FRA) ambiguity. A novel strategy of the ambiguity correction for those FR estimators is proposed and shown as a flow process, which is divided into pixel-level and image-level correction. The former is not yet recognized and thus is considered in particular. Finally, the validation experiments show a prominent performance of the proposed strategy.<\/jats:p>","DOI":"10.3390\/s18041158","type":"journal-article","created":{"date-parts":[[2018,4,10]],"date-time":"2018-04-10T13:06:08Z","timestamp":1523365568000},"page":"1158","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["A Novel Strategy of Ambiguity Correction for the Improved Faraday Rotation Estimator in Linearly Full-Polarimetric SAR Data"],"prefix":"10.3390","volume":"18","author":[{"given":"Jinhui","family":"Li","sequence":"first","affiliation":[{"name":"College of Electronic Science and Engineering, National University of Defense Technology, Changsha 410073, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yifei","family":"Ji","sequence":"additional","affiliation":[{"name":"College of Electronic Science and Engineering, National University of Defense Technology, Changsha 410073, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yongsheng","family":"Zhang","sequence":"additional","affiliation":[{"name":"College of Electronic Science and Engineering, National University of Defense Technology, Changsha 410073, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Qilei","family":"Zhang","sequence":"additional","affiliation":[{"name":"College of Electronic Science and Engineering, National University of Defense Technology, Changsha 410073, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Haifeng","family":"Huang","sequence":"additional","affiliation":[{"name":"College of Electronic Science and Engineering, National University of Defense Technology, Changsha 410073, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Zhen","family":"Dong","sequence":"additional","affiliation":[{"name":"College of Electronic Science and Engineering, National University of Defense Technology, Changsha 410073, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2018,4,10]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"189","DOI":"10.1088\/0959-7174\/14\/2\/008","article-title":"A survey of ionosphere effects on space-based radar","volume":"14","author":"Xu","year":"2004","journal-title":"Waves Random Media"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"2163","DOI":"10.1109\/LGRS.2014.2323232","article-title":"Ionospheric polarimetric dispersion effect on low-frequency spaceborne SAR imaging","volume":"11","author":"Li","year":"2014","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1007\/s11432-016-9064-1","article-title":"L-band geosynchronous SAR imaging degradations imposed by ionospheric irregularities","volume":"60","author":"Ji","year":"2017","journal-title":"China Sci. Inf. Sci."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"130","DOI":"10.13164\/re.2017.0130","article-title":"Analysis of background ionospheric effects on geosynchronous SAR imaging","volume":"26","author":"Ji","year":"2017","journal-title":"Radioengineering"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1115","DOI":"10.1109\/TGRS.2007.892583","article-title":"Analysis of the effects of the Faraday rotation on spaceborne polarimetric SAR observations at P-band","volume":"45","author":"Qi","year":"2007","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"301","DOI":"10.1109\/7.640287","article-title":"Effect of Faraday rotation on polarimetric SAR","volume":"34","author":"Gail","year":"1998","journal-title":"IEEE Trans. Aerosp. Electron. Syst."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"2735","DOI":"10.1109\/TGRS.2003.815399","article-title":"Faraday rotation effects on L-Band spaceborne SAR data","volume":"41","author":"Wright","year":"2003","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"846","DOI":"10.1109\/LGRS.2010.2047002","article-title":"Improved estimators of Faraday rotation in spaceborne polarimetric SAR data","volume":"7","author":"Chen","year":"2010","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"133","DOI":"10.1109\/LGRS.2013.2250478","article-title":"New Faraday rotation estimators based on polarimetric covariance matrix","volume":"11","author":"Li","year":"2014","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1607","DOI":"10.1109\/TGRS.2004.830163","article-title":"On the detection of Faraday rotation in linearly polarized L-band SAR backscatter signatures","volume":"42","author":"Freeman","year":"2004","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1617","DOI":"10.1109\/TGRS.2004.830161","article-title":"Calibration of linearly polarized polarimetric SAR data subject to Faraday rotation","volume":"42","author":"Freeman","year":"2004","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_12","first-page":"288","article-title":"Improved TEC retrieval based on spaceborne PolSAR data","volume":"52","author":"Wang","year":"2017","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1089","DOI":"10.1109\/PROC.1965.4097","article-title":"Effects of magneto-ionic propagation on the polarization scattering matrix","volume":"53","author":"Bickel","year":"1965","journal-title":"Proc. IEEE"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"3076","DOI":"10.1109\/TGRS.2008.2003002","article-title":"Prediction, detection, and correction of Faraday rotation in full-polarimetric L-band SAR data","volume":"46","author":"Meyer","year":"2008","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"4799","DOI":"10.1109\/TGRS.2013.2284635","article-title":"The Accuracy of Faraday Rotation Estimation in Satellite Synthetic Aperture Radar Images","volume":"52","author":"Rogers","year":"2014","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Burgin, M., and Moghaddam, M. (2014, January 13\u201318). Mitigation of Faraday Rotation effect for long-wavelength synthetic spaceborne radar data. Proceedings of the 2014 IEEE International Geoscience and Remote Sensing Symposium (IGARSS), Quebec City, QC, Canada.","DOI":"10.1109\/IGARSS.2014.6946940"},{"key":"ref_17","unstructured":"Guo, W., and Chen, J. (2014, January 13\u201318). Quantitative analysis of Faraday rotation impacts on image formation of spaceborne VHF\/UHF-SAR. Proceedings of the 2014 IEEE International Geoscience and Remote Sensing Symposium (IGARSS), Quebec City, QC, Canada."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/18\/4\/1158\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T15:00:15Z","timestamp":1760194815000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/18\/4\/1158"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2018,4,10]]},"references-count":17,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2018,4]]}},"alternative-id":["s18041158"],"URL":"https:\/\/doi.org\/10.3390\/s18041158","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2018,4,10]]}}}