{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,13]],"date-time":"2026-03-13T06:26:07Z","timestamp":1773383167099,"version":"3.50.1"},"reference-count":38,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2019,1,28]],"date-time":"2019-01-28T00:00:00Z","timestamp":1548633600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Spanish Ministry of Economy and Competition","award":["RYC-2016-20355"],"award-info":[{"award-number":["RYC-2016-20355"]}]},{"name":"Spanish Ministry of Economy and Competition","award":["AGL2017-83325-C4-3-R"],"award-info":[{"award-number":["AGL2017-83325-C4-3-R"]}]},{"name":"Spanish Ministry of Economy and Competition","award":["AGL2017-83325-C4-1-R"],"award-info":[{"award-number":["AGL2017-83325-C4-1-R"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Pastures are botanically diverse and difficult to characterize. Digital modeling of pasture biomass and quality by non-destructive methods can provide highly valuable support for decision-making. This study aimed to evaluate aerial and on-ground methods to characterize grass ley fields, estimating plant height, biomass and volume, using digital grass models. Two fields were sampled, one timothy-dominant and the other ryegrass-dominant. Both sensing systems allowed estimation of biomass, volume and plant height, which were compared with ground truth, also taking into consideration basic economical aspects. To obtain ground-truth data for validation, 10 plots of 1 m2 were manually and destructively sampled on each field. The studied systems differed in data resolution, thus in estimation capability. There was a reasonably good agreement between the UAV-based, the RGB-D-based estimates and the manual height measurements on both fields. RGB-D-based estimation correlated well with ground truth of plant height (     R 2  &gt; 0.80    ) for both fields, and with dry biomass (     R 2  = 0.88    ), only for the timothy field. RGB-D-based estimation of plant volume for ryegrass showed a high agreement (     R 2  = 0.87    ). The UAV-based system showed a weaker estimation capability for plant height and dry biomass (     R 2  &lt; 0.6    ). UAV-systems are more affordable, easier to operate and can cover a larger surface. On-ground techniques with RGB-D cameras can produce highly detailed models, but with more variable results than UAV-based models. On-ground RGB-D data can be effectively analysed with open source software, which is a cost reduction advantage, compared with aerial image analysis. Since the resolution for agricultural operations does not need fine identification the end-details of the grass plants, the use of aerial platforms could result a better option in grasslands.<\/jats:p>","DOI":"10.3390\/s19030535","type":"journal-article","created":{"date-parts":[[2019,1,29]],"date-time":"2019-01-29T03:40:55Z","timestamp":1548733255000},"page":"535","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":91,"title":["Comparing UAV-Based Technologies and RGB-D Reconstruction Methods for Plant Height and Biomass Monitoring on Grass Ley"],"prefix":"10.3390","volume":"19","author":[{"given":"Victor","family":"Rueda-Ayala","sequence":"first","affiliation":[{"name":"Department of Grassland and Livestock, Norwegian Institute of Bioeconomy Research, NIBIO S\u00e6rheim, Postvegen 213, 4353 Klepp Stasjon, Norway"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4592-3792","authenticated-orcid":false,"given":"Jos\u00e9","family":"Pe\u00f1a","sequence":"additional","affiliation":[{"name":"Institute of Agricultural Sciences, Consejo Superior Investigaciones Cient\u00edficas (CSIC), Serrano 115b, 28006 Madrid, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mats","family":"H\u00f6glind","sequence":"additional","affiliation":[{"name":"Department of Grassland and Livestock, Norwegian Institute of Bioeconomy Research, NIBIO S\u00e6rheim, Postvegen 213, 4353 Klepp Stasjon, Norway"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jos\u00e9","family":"Bengochea-Guevara","sequence":"additional","affiliation":[{"name":"Centre for Automation and Robotics, Consejo Superior Investigaciones Cient\u00edficas (CSIC), Ctra. de Campo Real km 0.200 La Poveda, 28500 Arganda del Rey (Madrid), Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Dionisio","family":"And\u00fajar","sequence":"additional","affiliation":[{"name":"Centre for Automation and Robotics, Consejo Superior Investigaciones Cient\u00edficas (CSIC), Ctra. de Campo Real km 0.200 La Poveda, 28500 Arganda del Rey (Madrid), Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2019,1,28]]},"reference":[{"key":"ref_1","first-page":"157","article-title":"Replacing Manual Rising Plate Meter Measurements with Low-cost UAV-Derived Sward Height Data in Grasslands for Spatial Monitoring","volume":"86","author":"Bareth","year":"2018","journal-title":"PFG J. 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