{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,23]],"date-time":"2026-10-23T21:00:00Z","timestamp":1792789200708,"version":"4.5.0"},"reference-count":56,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2017,4,30]],"date-time":"2017-04-30T00:00:00Z","timestamp":1493510400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100005357","name":"Agent\u00fara na Podporu V\u00fdskumu a V\u00fdvoja","doi-asserted-by":"publisher","award":["APVV-0069-12"],"award-info":[{"award-number":["APVV-0069-12"]}],"id":[{"id":"10.13039\/501100005357","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100006109","name":"Vedeck\u00e1 Grantov\u00e1 Agent\u00fara M\u0160VVa\u0160 SR a SAV","doi-asserted-by":"publisher","award":["1\/0804\/14"],"award-info":[{"award-number":["1\/0804\/14"]}],"id":[{"id":"10.13039\/501100006109","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Internal Project Agency of the Technical University in Zvolen","award":["1\/2016"],"award-info":[{"award-number":["1\/2016"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Forests"],"abstract":"<jats:p>This study focuses on the horizontal and vertical accuracy of point-clouds based on unmanned aerial vehicle (UAV) imagery. The DJI Phantom 3 Professional unmanned aerial vehicle and Agisoft PhotoScan Professional software were used for the evaluation. Three test sites with differing conditions (canopy openness, slope, terrain complexity, etc.) were used for comparison. The accuracy evaluation was aimed on positions of points placed on the ground. This is often disregarded under forest conditions as it is not possible to photogrammetrically reconstruct terrain that is covered by a fully-closed forest canopy. Therefore, such a measurement can only be conducted when there are gaps in the canopy or under leaf-off conditions in the case of deciduous forests. The reported sub-decimetre horizontal accuracy and vertical accuracy lower than 20 cm have proven that the method is applicable for survey, inventory, and various other tasks in forests. An analysis of ground control point (GCP) quantity and configuration showed that the quantity had only a minor effect on the accuracy in cases of plots with ~1-hectare area when using the aforementioned software. Therefore, methods increasing quality (precision, accuracy) of GCP positions should be preferred over the increase of quantity alone.<\/jats:p>","DOI":"10.3390\/f8050151","type":"journal-article","created":{"date-parts":[[2017,5,2]],"date-time":"2017-05-02T11:37:20Z","timestamp":1493725040000},"page":"151","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":85,"title":["Accuracy of Photogrammetric UAV-Based Point Clouds under Conditions of Partially-Open Forest Canopy"],"prefix":"10.3390","volume":"8","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6691-8357","authenticated-orcid":false,"given":"Juli\u00e1n","family":"Toma\u0161t\u00edk","sequence":"first","affiliation":[{"name":"Department of Forest management and Geodesy, Faculty of Forestry, Technical University in Zvolen, T.G. Masaryka 24, Zvolen 96053, Slovakia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8559-5757","authenticated-orcid":false,"given":"Martin","family":"Mokro\u0161","sequence":"additional","affiliation":[{"name":"Department of Forest management and Geodesy, Faculty of Forestry, Technical University in Zvolen, T.G. Masaryka 24, Zvolen 96053, Slovakia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"\u0160imon","family":"Salo\u0148","sequence":"additional","affiliation":[{"name":"Department of Forest management and Geodesy, Faculty of Forestry, Technical University in Zvolen, T.G. Masaryka 24, Zvolen 96053, Slovakia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Franti\u0161ek","family":"Chud\u00fd","sequence":"additional","affiliation":[{"name":"Department of Forest management and Geodesy, Faculty of Forestry, Technical University in Zvolen, T.G. Masaryka 24, Zvolen 96053, Slovakia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Daniel","family":"Tun\u00e1k","sequence":"additional","affiliation":[{"name":"Department of Forest management and Geodesy, Faculty of Forestry, Technical University in Zvolen, T.G. Masaryka 24, Zvolen 96053, Slovakia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2017,4,30]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2427","DOI":"10.1080\/01431161.2016.1252477","article-title":"Forestry applications of UAVs in Europe: A review","volume":"38","author":"Torresan","year":"2016","journal-title":"Int. J. Remote Sens."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Mikita, T., Janata, P., and Surov\u00fd, P. (2016). Forest stand inventory based on combined aerial and terrestrial close-range photogrammetry. 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