{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,6]],"date-time":"2026-01-06T13:05:19Z","timestamp":1767704719418,"version":"build-2065373602"},"reference-count":56,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2022,1,17]],"date-time":"2022-01-17T00:00:00Z","timestamp":1642377600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100018520","name":"Gheorghe Asachi Technical University of Ia\u0219i","doi-asserted-by":"publisher","award":["GI\/P1\/2021"],"award-info":[{"award-number":["GI\/P1\/2021"]}],"id":[{"id":"10.13039\/100018520","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>3D modelling of urban areas is an attractive and active research topic, as 3D digital models of cities are becoming increasingly common for urban management as a consequence of the constantly growing number of people living in cities. Viewed as a digital representation of the Earth\u2019s surface, an urban area modeled in 3D includes objects such as buildings, trees, vegetation and other anthropogenic structures, highlighting the buildings as the most prominent category. A city\u2019s 3D model can be created based on different data sources, especially LiDAR or photogrammetric point clouds. This paper\u2019s aim is to provide an end-to-end pipeline for 3D building modeling based on oblique UAS images only, the result being a parametrized 3D model with the Open Geospatial Consortium (OGC) CityGML standard, Level of Detail 2 (LOD2). For this purpose, a flight over an urban area of about 20.6 ha has been taken with a low-cost UAS, i.e., a DJI Phantom 4 Pro Professional (P4P), at 100 m height. The resulting UAS point cloud with the best scenario, i.e., 45 Ground Control Points (GCP), has been processed as follows: filtering to extract the ground points using two algorithms, CSF and terrain-mark; classification, using two methods, based on attributes only and a random forest machine learning algorithm; segmentation using local homogeneity implemented into Opals software; plane creation based on a region-growing algorithm; and plane editing and 3D model reconstruction based on piece-wise intersection of planar faces. The classification performed with ~35% training data and 31 attributes showed that the Visible-band difference vegetation index (VDVI) is a key attribute and 77% of the data was classified using only five attributes. The global accuracy for each modeled building through the workflow proposed in this study was around 0.15 m, so it can be concluded that the proposed pipeline is reliable.<\/jats:p>","DOI":"10.3390\/rs14020422","type":"journal-article","created":{"date-parts":[[2022,1,17]],"date-time":"2022-01-17T20:49:21Z","timestamp":1642452561000},"page":"422","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":12,"title":["3D Modeling of Urban Area Based on Oblique UAS Images\u2014An End-to-End Pipeline"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-5433-2201","authenticated-orcid":false,"given":"Valeria-Ersilia","family":"Oniga","sequence":"first","affiliation":[{"name":"Department of Terrestrial Measurements and Cadastre, Faculty of Hydrotechnical Engineering, Geodesy and Environmental Engineering, \u201cGheorghe Asachi\u201d Technical University of Iasi, Professor Dimitrie Mangeron Boulevard 67, 700050 Ia\u0219i, Romania"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ana-Ioana","family":"Breaban","sequence":"additional","affiliation":[{"name":"Department of Hydroamelioration and Environmental Protection, Faculty of Hydrotechnical Engineering, Geodesy and Environmental Engineering, \u201cGheorghe Asachi\u201d Technical University of Iasi, Professor Dimitrie Mangeron Boulevard 67, 700050 Ia\u0219i, Romania"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2348-7929","authenticated-orcid":false,"given":"Norbert","family":"Pfeifer","sequence":"additional","affiliation":[{"name":"Department of Geodesy and Geoinformation, Technische Universit\u00e4t Wien, Karlsplatz 13, 1040 Vienna, Austria"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Maximilian","family":"Diac","sequence":"additional","affiliation":[{"name":"Department of Terrestrial Measurements and Cadastre, Faculty of Hydrotechnical Engineering, Geodesy and Environmental Engineering, \u201cGheorghe Asachi\u201d Technical University of Iasi, Professor Dimitrie Mangeron Boulevard 67, 700050 Ia\u0219i, Romania"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2022,1,17]]},"reference":[{"key":"ref_1","unstructured":"United Nations (2018). 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