{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,27]],"date-time":"2025-10-27T04:57:22Z","timestamp":1761541042872,"version":"build-2065373602"},"reference-count":16,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2011,3,2]],"date-time":"2011-03-02T00:00:00Z","timestamp":1299024000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>The geometric characterisation of tree orchards is a high-precision activity comprising the accurate measurement and knowledge of the geometry and structure of the trees. Different types of sensors can be used to perform this characterisation. In this work a terrestrial LIDAR sensor (SICK LMS200) whose emission source was a 905-nm pulsed laser diode was used. Given the known dimensions of the laser beam cross-section (with diameters ranging from 12 mm at the point of emission to 47.2 mm at a distance of 8 m), and the known dimensions of the elements that make up the crops under study (flowers, leaves, fruits, branches, trunks), it was anticipated that, for much of the time, the laser beam would only partially hit a foreground target\/object, with the consequent problem of mixed pixels or edge effects. Understanding what happens in such situations was the principal objective of this work. With this in mind, a series of tests were set up to determine the geometry of the emitted beam and to determine the response of the sensor to different beam blockage scenarios. The main conclusions that were drawn from the results obtained were: (i) in a partial beam blockage scenario, the distance value given by the sensor depends more on the blocked radiant power than on the blocked surface area; (ii) there is an area that influences the measurements obtained that is dependent on the percentage of blockage and which ranges from 1.5 to 2.5 m with respect to the foreground target\/object. If the laser beam impacts on a second target\/object located within this range, this will affect the measurement given by the sensor. To interpret the information obtained from the point clouds provided by the LIDAR sensors, such as the volume occupied and the enclosing area, it is necessary to know the resolution and the process for obtaining this mesh of points and also to be aware of the problem associated with mixed pixels.<\/jats:p>","DOI":"10.3390\/s110302751","type":"journal-article","created":{"date-parts":[[2011,3,3]],"date-time":"2011-03-03T23:15:03Z","timestamp":1299194103000},"page":"2751-2772","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":39,"title":["Characterisation of the LMS200 Laser Beam under the Influence of Blockage Surfaces. Influence on 3D Scanning of Tree Orchards"],"prefix":"10.3390","volume":"11","author":[{"given":"Ricardo","family":"Sanz-Cortiella","sequence":"first","affiliation":[{"name":"Department of Agro-Forestry Engineering, University of Lleida, Avinguda Rovira Roure 191, 25198 Lleida, Spain"}]},{"given":"Jordi","family":"Llorens-Calveras","sequence":"additional","affiliation":[{"name":"Department of Agri Food Engineering and Biotechnology, Polytechnic University of Catalonia, Campus del Baix Llobregat, Edifici D4, Av. del Canal Ol\u00edmpic, s\/n 08860 Castelldefels, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6746-2830","authenticated-orcid":false,"given":"Joan R.","family":"Rosell-Polo","sequence":"additional","affiliation":[{"name":"Department of Agro-Forestry Engineering, University of Lleida, Avinguda Rovira Roure 191, 25198 Lleida, Spain"}]},{"given":"Eduard","family":"Gregorio-Lopez","sequence":"additional","affiliation":[{"name":"Department of Agro-Forestry Engineering, University of Lleida, Edifici CREA, C\/Pere de Cabrera s\/n 25001, Lleida, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8210-3262","authenticated-orcid":false,"given":"Jordi","family":"Palacin-Roca","sequence":"additional","affiliation":[{"name":"Department of Computer Science and Industrial Engineering, University of Lleida, Av. Jaume II 69, 25197 Lleida, Spain"}]}],"member":"1968","published-online":{"date-parts":[[2011,3,2]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"128","DOI":"10.1016\/j.biosystemseng.2008.10.009","article-title":"A Tractor-Mounted Scanning LIDAR for the Non-Destructive Measurement of Vegetative Volume and Surface Area of Tree-Row Plantations: A Comparison with Conventional Destructive Measurements","volume":"102","author":"Rosell","year":"2009","journal-title":"Biosyst. Eng"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1067","DOI":"10.1016\/j.rse.2009.01.017","article-title":"The Structural and Radiative Consistency of Three-Dimensional Tree Reconstructions from Terrestrial Lidar","volume":"113","author":"Cote","year":"2009","journal-title":"Remote Sens. Environ"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"571","DOI":"10.1080\/02827580410019562","article-title":"Three-Dimensional Reconstruction of Stems for Assessment of Taper, Sweep and Lean Based on Laser Scanning of Standing Trees","volume":"19","author":"Thies","year":"2004","journal-title":"Scand. J. Forest Res"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"320","DOI":"10.5589\/m08-027","article-title":"Retrieving Crown Leaf Area Index from an Individual Tree using Ground-Based Lidar Data","volume":"34","author":"Moorthy","year":"2008","journal-title":"Can. J. Remote Sens"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1505","DOI":"10.1016\/j.agrformet.2009.04.008","article-title":"Obtaining the Three-Dimensional Structure of Tree Orchards from Remote 2D Terrestrial LIDAR Scanning","volume":"149","author":"Rosell","year":"2009","journal-title":"Agric. For. Meteorol"},{"key":"ref_6","unstructured":"Chang, YC, Kuwabara, H, and Yamamoto, Y (2008, January July). Novel Application of a Laser Range Finder with Vision System for Wheeled Mobile Robot. Xian, China."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1573","DOI":"10.1016\/j.agrformet.2009.04.010","article-title":"3D Upscaling of Transpiration from Leaf to Tree using Ground-Based LiDAR: Application on a Mediterranean Holm Oak (\/iQuercus Ilex\/L.) Tree","volume":"149","author":"Zande","year":"2009","journal-title":"Agric. For. Meteorol"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"147","DOI":"10.1016\/j.agrformet.2006.09.007","article-title":"Influence of Measurement Set-Up of Ground-Based LiDAR for Derivation of Tree Structure","volume":"141","author":"Zande","year":"2006","journal-title":"Agric. For. Meteorol"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1080","DOI":"10.1016\/j.cropro.2006.02.011","article-title":"Optimising the Adjustment of Label-Recommended Dose Rate for Orchard Spraying","volume":"25","author":"Walklate","year":"2006","journal-title":"Crop Protection"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.compag.2010.03.007","article-title":"A Laser Scanning System for Estimating Wind Velocity Reduction through Tree Windbreaks","volume":"73","author":"Lee","year":"2010","journal-title":"Comput. Electron. Agric"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1377","DOI":"10.1109\/TIM.2007.900126","article-title":"Real-Time Tree-Foliage Surface Estimation using a Ground Laser Scanner","volume":"56","author":"Palacin","year":"2007","journal-title":"IEEE Trans. Instr. Meas"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1420","DOI":"10.1016\/j.agrformet.2010.07.005","article-title":"Sensitivity of Tree Volume Measurement to Trajectory Errors from a Terrestrial LIDAR Scanner","volume":"150","author":"Palleja","year":"2010","journal-title":"Agric. For. Meteorol"},{"key":"ref_13","unstructured":"Ye, C, and Borenstein, J (2002, January May). Characterization of a 2-D Laser Scanner for Mobile Robot Obstacle Negotiation. Washington, DC, USA."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"52","DOI":"10.1117\/12.486764","article-title":"A New Terrain Mapping Method for Mobile Robots Obstacle Negotiation","volume":"5083","author":"Ye","year":"2003","journal-title":"Proc. SPIE"},{"key":"ref_15","unstructured":"SICK A.G. Laser Measurement Systems (2003). Technical Specifications Manual, SICK, LMS 200\/211\/220\/221\/291."},{"key":"ref_16","unstructured":"SICK A.G (2003). Telegrams for Operating\/Configuring the LMS2XX Laser Measurement Systems, Firmware version V.2.10\/X1.14."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/11\/3\/2751\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T21:55:25Z","timestamp":1760219725000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/11\/3\/2751"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2011,3,2]]},"references-count":16,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2011,3]]}},"alternative-id":["s110302751"],"URL":"https:\/\/doi.org\/10.3390\/s110302751","relation":{},"ISSN":["1424-8220"],"issn-type":[{"type":"electronic","value":"1424-8220"}],"subject":[],"published":{"date-parts":[[2011,3,2]]}}}