{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,19]],"date-time":"2026-03-19T14:35:59Z","timestamp":1773930959027,"version":"3.50.1"},"reference-count":35,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2022,2,8]],"date-time":"2022-02-08T00:00:00Z","timestamp":1644278400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100012166","name":"National Key Research and Development Program of China","doi-asserted-by":"publisher","award":["2021YFC1523401"],"award-info":[{"award-number":["2021YFC1523401"]}],"id":[{"id":"10.13039\/501100012166","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Technology Innovation Center for Land Engineering and Human Settlements, Shaanxi Land Engineering Construction Group Co., Ltd and Xi'an Jiaotong University","award":["2021WHZ0080"],"award-info":[{"award-number":["2021WHZ0080"]}]},{"name":"Aerospace Information Research Institute Chinese Academy of Science","award":["3R2210016423"],"award-info":[{"award-number":["3R2210016423"]}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["41974129"],"award-info":[{"award-number":["41974129"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Graduate Innovation Fund of Jilin University","award":["101832020CX226"],"award-info":[{"award-number":["101832020CX226"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>A full-polarimetric ground penetrating radar (FP-GPR) uses an antenna array to detect subsurface anomalies. Compared to the traditional GPR, FP-GPR can obtain more abundant information about the subsurface. However, in field FP-GPR measurements, the arrival time of the received electromagnetic (EM) waves from different channels cannot be strictly aligned due to the limitations of human operation errors and the craftsmanship of the equipment. Small misalignments between the radargrams acquired from different channels of an FP-GPR can lead to erroneous identification results of the classic Freeman decomposition (FD) method. Here, we propose a local Freeman decomposition (LFD) method to enhance the robustness of the classic FD method when managing with misaligned FP-GPR data. The tests on three typical targets demonstrate that misalignments will severely interfere with the imaging and the identification results of the classic FD method for the plane and dihedral scatterers. In contrast, the proposed LFD method can produce smooth images and accurate identification results. Besides, the identification of the volume scatterer is not affected by misalignments. A test of ice-fracture detection further verifies the capability of the LFD method in field measurements. Due to the different relative magnitudes of the permittivity of the media on two sides of the interfaces, the ice surface and ice fracture show the features of surface-like and double-bounce scattering, respectively. However, the definition of double-bounce scattering is different from the definition in polarimetric synthetic aperture radar (SAR). Finally, a quantitative analysis shows that the sensitivities of the FD and LFD methods to misalignments are related to both the type of target and the polarized mode of the misaligned data. The tolerable range of the LFD method for misalignments is approximately \u00b10.2 times the wavelength of the EM wave, which is much wider than that of the FD method. In most cases, the LFD method can guarantee an accurate result of identification.<\/jats:p>","DOI":"10.3390\/rs14030804","type":"journal-article","created":{"date-parts":[[2022,2,8]],"date-time":"2022-02-08T23:42:20Z","timestamp":1644363740000},"page":"804","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":17,"title":["Local Freeman Decomposition for Robust Imaging and Identification of Subsurface Anomalies Using Misaligned Full-Polarimetric GPR Data"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-1887-3171","authenticated-orcid":false,"given":"Haoqiu","family":"Zhou","sequence":"first","affiliation":[{"name":"College of Geo-Exploration Science and Technology, Jilin University, No. 938 Xi MinZhu Street, Changchun 130026, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7451-9145","authenticated-orcid":false,"given":"Xuan","family":"Feng","sequence":"additional","affiliation":[{"name":"College of Geo-Exploration Science and Technology, Jilin University, No. 938 Xi MinZhu Street, Changchun 130026, China"},{"name":"Key Laboratory of Applied Geophysics, Ministry of Natural Resources, Jilin University, Changchun 130026, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5196-987X","authenticated-orcid":false,"given":"Zejun","family":"Dong","sequence":"additional","affiliation":[{"name":"College of Geo-Exploration Science and Technology, Jilin University, No. 938 Xi MinZhu Street, Changchun 130026, China"}]},{"given":"Cai","family":"Liu","sequence":"additional","affiliation":[{"name":"College of Geo-Exploration Science and Technology, Jilin University, No. 938 Xi MinZhu Street, Changchun 130026, China"},{"name":"Key Laboratory of Applied Geophysics, Ministry of Natural Resources, Jilin University, Changchun 130026, China"}]},{"given":"Wenjing","family":"Liang","sequence":"additional","affiliation":[{"name":"College of Geo-Exploration Science and Technology, Jilin University, No. 938 Xi MinZhu Street, Changchun 130026, China"}]},{"given":"Yafei","family":"An","sequence":"additional","affiliation":[{"name":"College of Geo-Exploration Science and Technology, Jilin University, No. 938 Xi MinZhu Street, Changchun 130026, China"}]}],"member":"1968","published-online":{"date-parts":[[2022,2,8]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"99","DOI":"10.1088\/0266-5611\/20\/6\/S07","article-title":"Pre-stack migration applied to GPR for landmine detection","volume":"20","author":"Feng","year":"2004","journal-title":"Inverse Prob."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"J23","DOI":"10.1190\/1.3103253","article-title":"3D polarimetric GPR coherency attributes and full-waveform inversion of transmission data for characterizing fractured rock","volume":"74","author":"Sassen","year":"2009","journal-title":"Geophysics"},{"key":"ref_3","first-page":"736","article-title":"Subsurface Utility Extraction and Characterization: Combining GPR Symmetry and Polarization Attributes","volume":"50","author":"Tronicke","year":"2011","journal-title":"IEEE Trans. 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