{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T01:09:29Z","timestamp":1760231369019,"version":"build-2065373602"},"reference-count":33,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2022,9,17]],"date-time":"2022-09-17T00:00:00Z","timestamp":1663372800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["42104134","JJKH20221015KJ","2017YFC0601606"],"award-info":[{"award-number":["42104134","JJKH20221015KJ","2017YFC0601606"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Scientific Research Project of Education Department of Jilin Province","award":["42104134","JJKH20221015KJ","2017YFC0601606"],"award-info":[{"award-number":["42104134","JJKH20221015KJ","2017YFC0601606"]}]},{"DOI":"10.13039\/501100012166","name":"National Key Research and Development Program of China","doi-asserted-by":"publisher","award":["42104134","JJKH20221015KJ","2017YFC0601606"],"award-info":[{"award-number":["42104134","JJKH20221015KJ","2017YFC0601606"]}],"id":[{"id":"10.13039\/501100012166","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>As an effective underground imaging method, the joint inversion of the gravity and magnetic data has an important application in the comprehensive interpretation of mineral exploration, and unstructured modeling is the key to accurately solving its topographic problem. However, the traditional tetrahedral grid can only impose the gradient-based constraints approximately, owing to its poor arrangement regularity. To address the difficulty of applying a cross-gradient constraint in an unstructured grid, we propose a joint inversion based on a combined hexahedral grid, which regularly divides the shallow part into curved hexahedrons and the deep part into regular hexahedrons. Instead of a cross-gradient in the spatial sense, we construct a geometric sense \u201ccross-gradient\u201d for a structural constraint to reduce the influence of approximation. In addition, we further correct the traditional sensitivity-based weighting function according to element volume, to make it suitable for an unstructured grid. Model tests indicate that the new grid can impose the cross-gradient constraint more strongly, and the proposed correction can effectively solve the false anomaly caused by the element volume difference. Finally, we apply our method to the measured data from a mining area in Huzhong, Heilongjiang Province, China, and successfully invert out the specific location of a known skarn deposit, which further proves its practicability.<\/jats:p>","DOI":"10.3390\/rs14184651","type":"journal-article","created":{"date-parts":[[2022,9,19]],"date-time":"2022-09-19T04:49:22Z","timestamp":1663562962000},"page":"4651","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Joint Inversion of 3D Gravity and Magnetic Data under Undulating Terrain Based on Combined Hexahedral Grid"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2204-7179","authenticated-orcid":false,"given":"Haoyuan","family":"He","sequence":"first","affiliation":[{"name":"College of Geo-Exploration Sciences and Technology, Jilin University, Changchun 130026, China"}]},{"given":"Tonglin","family":"Li","sequence":"additional","affiliation":[{"name":"College of Geo-Exploration Sciences and Technology, Jilin University, Changchun 130026, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7870-2238","authenticated-orcid":false,"given":"Rongzhe","family":"Zhang","sequence":"additional","affiliation":[{"name":"College of Geo-Exploration Sciences and Technology, Jilin University, Changchun 130026, China"}]}],"member":"1968","published-online":{"date-parts":[[2022,9,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"730","DOI":"10.1190\/1.1440973","article-title":"Analytical expressions for gravity anomalies due to homogeneous polyhedral bodies and translations into magnetic anomalies","volume":"44","author":"Okabe","year":"1979","journal-title":"Geophysics"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"G69","DOI":"10.1190\/geo2012-0246.1","article-title":"Forward modeling of gravity data using finite-volume and finite-element methods on unstructured grids","volume":"78","author":"Jahandari","year":"2013","journal-title":"Geophysics"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"104340","DOI":"10.1016\/j.jappgeo.2021.104340","article-title":"Forward modelling of gravity data on unstructured grids using an adaptive mimetic finite-difference method","volume":"190","author":"Jahandari","year":"2021","journal-title":"J. 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