{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,1]],"date-time":"2026-06-01T15:28:40Z","timestamp":1780327720934,"version":"3.54.1"},"reference-count":59,"publisher":"MDPI AG","issue":"17","license":[{"start":{"date-parts":[[2020,8,19]],"date-time":"2020-08-19T00:00:00Z","timestamp":1597795200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100002341","name":"Academy of Finland","doi-asserted-by":"publisher","award":["272195"],"award-info":[{"award-number":["272195"]}],"id":[{"id":"10.13039\/501100002341","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100002341","name":"Academy of Finland","doi-asserted-by":"publisher","award":["307362"],"award-info":[{"award-number":["307362"]}],"id":[{"id":"10.13039\/501100002341","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Terrestrial laser scanning (TLS) has been adopted as a feasible technique to digitize trees and forest stands, providing accurate information on tree and forest structural attributes. However, there is limited understanding on how a variety of forest structural changes can be quantified using TLS in boreal forest conditions. In this study, we assessed the accuracy and feasibility of TLS in quantifying changes in the structure of boreal forests. We collected TLS data and field reference from 37 sample plots in 2014 (T1) and 2019 (T2). Tree stems typically have planar, vertical, and cylindrical characteristics in a point cloud, and thus we applied surface normal filtering, point cloud clustering, and RANSAC-cylinder filtering to identify these geometries and to characterize trees and forest stands at both time points. The results strengthened the existing knowledge that TLS has the capacity to characterize trees and forest stands in space and showed that TLS could characterize structural changes in time in boreal forest conditions. Root-mean-square-errors (RMSEs) in the estimates for changes in the tree attributes were 0.99\u20131.22 cm for diameter at breast height (\u0394dbh), 44.14\u201355.49 cm2 for basal area (\u0394g), and 1.91\u20134.85 m for tree height (\u0394h). In general, tree attributes were estimated more accurately for Scots pine trees, followed by Norway spruce and broadleaved trees. At the forest stand level, an RMSE of 0.60\u20131.13 cm was recorded for changes in basal area-weighted mean diameter (\u0394Dg), 0.81\u20132.26 m for changes in basal area-weighted mean height (\u0394Hg), 1.40\u20132.34 m2\/ha for changes in mean basal area (\u0394G), and 74\u2013193 n\/ha for changes in the number of trees per hectare (\u0394TPH). The plot-level accuracy was higher in Scots pine-dominated sample plots than in Norway spruce-dominated and mixed-species sample plots. TLS-derived tree and forest structural attributes at time points T1 and T2 differed significantly from each other (p &lt; 0.05). If there was an increase or decrease in dbh, g, h, height of the crown base, crown ratio, Dg, Hg, or G recorded in the field, a similar outcome was achieved by using TLS. Our results provided new information on the feasibility of TLS for the purposes of forest ecosystem growth monitoring.<\/jats:p>","DOI":"10.3390\/rs12172672","type":"journal-article","created":{"date-parts":[[2020,8,19]],"date-time":"2020-08-19T09:22:31Z","timestamp":1597828951000},"page":"2672","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":20,"title":["Structural Changes in Boreal Forests Can Be Quantified Using Terrestrial Laser Scanning"],"prefix":"10.3390","volume":"12","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2648-523X","authenticated-orcid":false,"given":"Tuomas","family":"Yrttimaa","sequence":"first","affiliation":[{"name":"School of Forest Sciences, University of Eastern Finland, 80101 Joensuu, Finland"},{"name":"Department of Forest Sciences, University of Helsinki, 00014 Helsinki, Finland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9036-8591","authenticated-orcid":false,"given":"Ville","family":"Luoma","sequence":"additional","affiliation":[{"name":"Department of Forest Sciences, University of Helsinki, 00014 Helsinki, Finland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2730-8892","authenticated-orcid":false,"given":"Ninni","family":"Saarinen","sequence":"additional","affiliation":[{"name":"School of Forest Sciences, University of Eastern Finland, 80101 Joensuu, Finland"},{"name":"Department of Forest Sciences, University of Helsinki, 00014 Helsinki, Finland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ville","family":"Kankare","sequence":"additional","affiliation":[{"name":"School of Forest Sciences, University of Eastern Finland, 80101 Joensuu, Finland"},{"name":"Department of Forest Sciences, University of Helsinki, 00014 Helsinki, Finland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Samuli","family":"Junttila","sequence":"additional","affiliation":[{"name":"School of Forest Sciences, University of Eastern Finland, 80101 Joensuu, Finland"},{"name":"Department of Forest Sciences, University of Helsinki, 00014 Helsinki, Finland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Markus","family":"Holopainen","sequence":"additional","affiliation":[{"name":"Department of Forest Sciences, University of Helsinki, 00014 Helsinki, Finland"},{"name":"Department of Remote Sensing and Photogrammetry, Finnish Geospatial Research Institute, National Land Survey of Finland (NLS), 02431 Masala, Finland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Juha","family":"Hyypp\u00e4","sequence":"additional","affiliation":[{"name":"Department of Remote Sensing and Photogrammetry, Finnish Geospatial Research Institute, National Land Survey of Finland (NLS), 02431 Masala, Finland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6552-9122","authenticated-orcid":false,"given":"Mikko","family":"Vastaranta","sequence":"additional","affiliation":[{"name":"School of Forest Sciences, University of Eastern Finland, 80101 Joensuu, Finland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,8,19]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"76","DOI":"10.1016\/j.isprsjprs.2019.03.007","article-title":"Detecting and characterizing downed dead wood using terrestrial laser scanning","volume":"151","author":"Yrttimaa","year":"2019","journal-title":"ISPRS J. Photogramm. Remote Sens."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"66","DOI":"10.1080\/02827581.2015.1056751","article-title":"Using multi-source data to map and model the predisposition of forests to wind disturbance","volume":"31","author":"Saarinen","year":"2016","journal-title":"Scand. J. For. Res."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Carvajal-Ram\u00edrez, F., da Silva, J.R.M., Ag\u00fcera-Vega, F., Mart\u00ednez-Carricondo, P., Serrano, J., and Moral, F.J. (2019). Evaluation of fire severity indices based on pre- and post-fire multispectral imagery sensed from UAV. Remote Sens., 11.","DOI":"10.3390\/rs11090993"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"8180","DOI":"10.3390\/rs70608180","article-title":"Assessing metrics for estimating fire induced change in the forest understorey structure using terrestrial laser scanning","volume":"7","author":"Gupta","year":"2015","journal-title":"Remote Sens."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1682","DOI":"10.3390\/f5071682","article-title":"Outlook for the next generation\u2019s precision forestry in Finland","volume":"5","author":"Holopainen","year":"2014","journal-title":"Forests"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"242","DOI":"10.3390\/ijgi1030242","article-title":"Detecting changes in forest structure over time with bi-temporal terrestrial laser scanning data","volume":"1","author":"Liang","year":"2012","journal-title":"ISPRS Int. J. Geo-Inf."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"959","DOI":"10.1007\/s13595-011-0102-2","article-title":"The use of terrestrial LiDAR technology in forest science: Application fields, benefits and challenges","volume":"68","author":"Dassot","year":"2011","journal-title":"Ann. For. Sci."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"63","DOI":"10.1016\/j.isprsjprs.2016.01.006","article-title":"Terrestrial laser scanning in forest inventories","volume":"115","author":"Liang","year":"2016","journal-title":"ISPRS J. Photogramm. Remote Sens."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"239","DOI":"10.1007\/s40725-015-0025-5","article-title":"Terrestrial laser scanning for plot-scale forest measurement","volume":"1","author":"Newnham","year":"2015","journal-title":"Curr. For. Rep."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Yrttimaa, T., Saarinen, N., Kankare, V., Liang, X., Hyypp\u00e4, J., Holopainen, M., and Vastaranta, M. (2019). Investigating the feasibility of multi-scan terrestrial laser scanning to characterize tree communities in southern boreal forests. Remote Sens., 11.","DOI":"10.3390\/rs11121423"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1579","DOI":"10.1080\/01431160701736406","article-title":"Automatic forest inventory parameter determination from terrestrial laser scanner data","volume":"29","author":"Maas","year":"2008","journal-title":"Int. J. Remote Sens."},{"key":"ref_12","unstructured":"Aschoff, T., Thies, M., and Spiecker, H. (2004, January 12\u201323). Describing forest stands using terrestrial laser-scanning. Proceedings of the 20th ISPRS World Congress, Istanbul, Turkey."},{"key":"ref_13","first-page":"164","article-title":"Automatic dendrometry: Tree detection, tree height and diameter estimation using terrestrial laser scanning","volume":"69","author":"Cabo","year":"2018","journal-title":"Int. J. Appl. Earth Obs. Geoinf."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Zhang, W., Wan, P., Wang, T., Cai, S., Chen, Y., Jin, X., and Yan, G. (2019). A novel approach for the detection of standing tree stems from plot-level terrestrial laser scanning data. Remote Sens., 11.","DOI":"10.3390\/rs11020211"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"661","DOI":"10.1109\/TGRS.2011.2161613","article-title":"Automatic stem mapping using single-scan terrestrial laser scanning","volume":"50","author":"Liang","year":"2012","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Heinzel, J., and Huber, M. (2016). Detecting tree stems from volumetric TLS data in forest environments with rich understory. Remote Sens., 9.","DOI":"10.3390\/rs9010009"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"491","DOI":"10.3390\/rs5020491","article-title":"Fast automatic precision tree models from terrestrial laser scanner data","volume":"5","author":"Raumonen","year":"2013","journal-title":"Remote Sens."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1069","DOI":"10.3390\/f5051069","article-title":"Highly accurate tree models derived from terrestrial laser scan data: A method description","volume":"5","author":"Hackenberg","year":"2014","journal-title":"Forests"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"4581","DOI":"10.3390\/rs70404581","article-title":"Analysis of geometric primitives in quantitative structure models of tree stems","volume":"7","author":"Raumonen","year":"2015","journal-title":"Remote Sens."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Olofsson, K., and Holmgren, J. (2016). Single tree stem profile detection using terrestrial laser scanner data, flatness saliency features and curvature properties. Forests, 7.","DOI":"10.3390\/f7090207"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"140","DOI":"10.1016\/j.rse.2017.04.030","article-title":"Data acquisition considerations for terrestrial laser scanning of forest plots","volume":"196","author":"Wilkes","year":"2017","journal-title":"Remote Sens. Environ."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"137","DOI":"10.1016\/j.isprsjprs.2018.06.021","article-title":"International benchmarking of terrestrial laser scanning approaches for forest inventories","volume":"144","author":"Liang","year":"2018","journal-title":"ISPRS J. Photogramm. Remote Sens."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"3057","DOI":"10.1109\/TGRS.2019.2947198","article-title":"Improved supervised learning-based approach for leaf and wood classification from LiDAR point clouds of forests","volume":"58","author":"Moorthy","year":"2020","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"20170045","DOI":"10.1098\/rsfs.2017.0045","article-title":"Non-intersecting leaf insertion algorithm for tree structure models","volume":"8","author":"Raumonen","year":"2018","journal-title":"Interface Focus"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"680","DOI":"10.1111\/2041-210X.13144","article-title":"Leaf and wood classification framework for terrestrial LiDAR point clouds","volume":"10","author":"Vicari","year":"2019","journal-title":"Methods Ecol. Evol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"679","DOI":"10.1109\/TGRS.2015.2459716","article-title":"Improved salient feature-based approach for automatically separating photosynthetic and non-photosynthetic components within terrestrial LiDAR point cloud data of forest canopies","volume":"54","author":"Ma","year":"2016","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"82","DOI":"10.1016\/j.agrformet.2013.09.005","article-title":"On seeing the wood from the leaves and the role of voxel size in determining leaf area distribution of forests with terrestrial LiDAR","volume":"184","author":"Baldocchi","year":"2014","journal-title":"Agric. For. Meteorol."},{"key":"ref_28","first-page":"43","article-title":"Foliar and woody materials discriminated using terrestrial LiDAR in a mixed natural forest","volume":"64","author":"Zhu","year":"2018","journal-title":"Int. J. Appl. Earth Obs. Geoinf."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"111264","DOI":"10.1016\/j.rse.2019.111264","article-title":"The potential of dual-wavelength terrestrial LiDAR in early detection of Ips typographus (L.) infestation\u2014Leaf water content as a proxy","volume":"231","author":"Junttila","year":"2019","journal-title":"Remote Sens. Environ."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"304","DOI":"10.1016\/j.foreco.2014.01.038","article-title":"Multi-temporal terrestrial laser scanning for modeling tree biomass change","volume":"318","author":"Srinivasan","year":"2014","journal-title":"For. Ecol. Manag."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"3906","DOI":"10.3390\/rs6053906","article-title":"Change detection of tree biomass with terrestrial laser scanning and quantitative structure modelling","volume":"6","author":"Kaasalainen","year":"2014","journal-title":"Remote Sens."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"172","DOI":"10.3832\/ifor2138-009","article-title":"Terrestrial laser scanning as a tool for assessing tree growth","volume":"10","author":"Sheppard","year":"2017","journal-title":"IFOREST"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"6800","DOI":"10.1002\/ece3.4193","article-title":"A high-resolution approach for the spatiotemporal analysis of forest canopy space using terrestrial laser scanning data","volume":"8","author":"Hess","year":"2018","journal-title":"Ecol. Evol."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"2130","DOI":"10.1111\/ele.13400","article-title":"Neighbour species richness and local structural variability modulate aboveground allocation patterns and crown morphology of individual trees","volume":"22","author":"Kunz","year":"2019","journal-title":"Ecol. Lett."},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Luoma, V., Saarinen, N., Kankare, V., Tanhuanp\u00e4\u00e4, T., Kaartinen, H., Kukko, A., Holopainen, M., Hyypp\u00e4, J., and Vastaranta, M. (2019). Examining changes in stem taper and volume growth with two-date 3D point clouds. Forests, 10.","DOI":"10.3390\/f10050382"},{"key":"ref_36","first-page":"268","article-title":"Airborne laser scanning outperforms the alternative 3D techniques in capturing variation in tree height and forest density in southern boreal forests","volume":"28","author":"Vastaranta","year":"2018","journal-title":"Baltic For."},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Luoma, V., Saarinen, N., Wulder, M., White, J., Vastaranta, M., Holopainen, M., and Hyypp\u00e4, J. (2017). Assessing precision in conventional field measurements of individual tree attributes. Forests, 8.","DOI":"10.3390\/f8020038"},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Ritter, T., Schwarz, M., Tockner, A., Leisch, F., and Nothdurft, A. (2017). Automatic mapping of forest stands based on three-dimensional point clouds derived from terrestrial laser-scanning. Forests, 8.","DOI":"10.3390\/f8080265"},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Yrttimaa, T., Saarinen, N., Kankare, V., Hynynen, J., Huuskonen, S., Holopainen, M., Hyypp\u00e4, J., and Vastaranta, M. (2020). Performance of terrestrial laser scanning to characterize managed Scots pine (Pinus sylvestris L.) stands is dependent on forest structural variation. EarthArXiv.","DOI":"10.31223\/OSF.IO\/YBS7C"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"589","DOI":"10.14358\/PERS.70.5.589","article-title":"Seeing the trees in the forest","volume":"70","author":"Popescu","year":"2004","journal-title":"Photogramm. Eng. Remote Sens."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"21","DOI":"10.1016\/1047-3203(90)90014-M","article-title":"Morphological segmentation","volume":"1","author":"Meyer","year":"1990","journal-title":"J. Visual Commun. Image Represent."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"140","DOI":"10.1016\/j.isprsjprs.2016.11.012","article-title":"Feasibility of terrestrial laser scanning for collecting stem volume information from single trees","volume":"123","author":"Saarinen","year":"2017","journal-title":"ISPRS J. Photogramm. Remote Sens."},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Abegg, M., K\u00fckenbrink, D., Zell, J., Schaepman, M.E., and Morsdorf, F. (2017). Terrestrial laser scanning for forest inventories\u2014Tree diameter distribution and scanner location impact on occlusion. For. Trees Livelihoods, 8.","DOI":"10.3390\/f8060184"},{"key":"ref_44","doi-asserted-by":"crossref","unstructured":"Gollob, C., Ritter, T., Wassermann, C., and Nothdurft, A. (2019). Influence of scanner position and plot size on the accuracy of tree detection and diameter estimation using terrestrial laser scanning on forest inventory plots. Remote Sens., 11.","DOI":"10.3390\/rs11131602"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"355","DOI":"10.1139\/cjfr-2012-0347","article-title":"Arrangement of terrestrial laser scanner positions for area-wide stem mapping of natural forests","volume":"43","author":"Trochta","year":"2013","journal-title":"Can. J. For. Res."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"249","DOI":"10.1016\/j.agrformet.2019.01.033","article-title":"Quantifying 3D structure and occlusion in dense tropical and temperate forests using close-range LiDAR","volume":"268","author":"Schneider","year":"2019","journal-title":"Agric. For. Meteorol."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"132","DOI":"10.1016\/j.isprsjprs.2018.11.008","article-title":"Is field-measured tree height as reliable as believed\u2014A comparison study of tree height estimates from field measurement, airborne laser scanning and terrestrial laser scanning in a boreal forest","volume":"147","author":"Wang","year":"2019","journal-title":"ISPRS J. Photogramm. Remote Sens."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"431","DOI":"10.1093\/forestry\/77.5.431","article-title":"A new girth band for measuring stem diameter changes","volume":"77","author":"Pesonen","year":"2004","journal-title":"Forestry"},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"1504","DOI":"10.1109\/LGRS.2013.2297418","article-title":"The use of a mobile laser scanning system for mapping large forest plots","volume":"11","author":"Liang","year":"2014","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"11712","DOI":"10.3390\/s120911712","article-title":"Multiplatform mobile laser scanning: Usability and performance","volume":"12","author":"Kukko","year":"2012","journal-title":"Sensors"},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"246","DOI":"10.1016\/j.isprsjprs.2020.01.018","article-title":"Accurate derivation of stem curve and volume using backpack mobile laser scanning","volume":"161","author":"Kukko","year":"2020","journal-title":"ISPRS J. Photogramm. Remote Sens."},{"key":"ref_52","doi-asserted-by":"crossref","unstructured":"Bauwens, S., Bartholomeus, H., Calders, K., and Lejeune, P. (2016). Forest inventory with terrestrial LiDAR: A comparison of static and hand-held mobile laser scanning. Forests, 7.","DOI":"10.3390\/f7060127"},{"key":"ref_53","doi-asserted-by":"crossref","unstructured":"Chen, S., Liu, H., Feng, Z., Shen, C., and Chen, P. (2019). Applicability of personal laser scanning in forestry inventory. PLoS ONE, 14.","DOI":"10.1371\/journal.pone.0211392"},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"199","DOI":"10.1016\/j.isprsjprs.2017.09.006","article-title":"Graph SLAM correction for single scanner MLS forest data under boreal forest canopy","volume":"132","author":"Kukko","year":"2017","journal-title":"ISPRS J. Photogramm. Remote Sens."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"514","DOI":"10.1016\/j.isprsjprs.2010.08.002","article-title":"A low-cost multi-sensoral mobile mapping system and its feasibility for tree measurements","volume":"65","author":"Jaakkola","year":"2010","journal-title":"ISPRS J. Photogramm. Remote Sens."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"465","DOI":"10.1016\/j.isprsjprs.2018.11.001","article-title":"Estimating forest structural attributes using UAV-LiDAR data in Ginkgo plantations","volume":"146","author":"Liu","year":"2018","journal-title":"ISPRS J. Photogramm. Remote Sens."},{"key":"ref_57","doi-asserted-by":"crossref","unstructured":"Jaakkola, A., Hyypp\u00e4, J., Yu, X., Kukko, A., Kaartinen, H., Liang, X., Hyypp\u00e4, H., and Wang, Y. (2017). Autonomous collection of forest field reference\u2014The outlook and a first step with UAV laser scanning. Remote Sens., 9.","DOI":"10.3390\/rs9080785"},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"41","DOI":"10.1016\/j.isprsjprs.2020.03.021","article-title":"Under-canopy UAV laser scanning for accurate forest field measurements","volume":"164","author":"Hakala","year":"2020","journal-title":"ISPRS J. Photogramm. Remote Sens."},{"key":"ref_59","doi-asserted-by":"crossref","unstructured":"Yrttimaa, T., Saarinen, N., Kankare, V., Viljanen, N., Hynynen, J., Huuskonen, S., Holopainen, M., Hyypp\u00e4, J., Honkavaara, E., and Vastaranta, M. (2020). Multisensorial close-range sensing generates benefits for characterization of managed Scots pine (Pinus sylvestris L.) stands. ISPRS Int. J. Geo-Inf., 9.","DOI":"10.20944\/preprints202003.0399.v1"}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/12\/17\/2672\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T10:02:56Z","timestamp":1760176976000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/12\/17\/2672"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,8,19]]},"references-count":59,"journal-issue":{"issue":"17","published-online":{"date-parts":[[2020,9]]}},"alternative-id":["rs12172672"],"URL":"https:\/\/doi.org\/10.3390\/rs12172672","relation":{"has-preprint":[{"id-type":"doi","id":"10.20944\/preprints202007.0154.v1","asserted-by":"object"}]},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,8,19]]}}}