Forest laser scanning from the field is a useful technology for complementing and control of sample plot information which is measured via traditional methods of fieldwork in the context of classic forest inventory. Such laser scanners remain, however, expensive and require professional handling. In this work the novel Apple lidar technology on commercial iPhone devices was evaluated for measuring tree diameter at breast height (DBH) and horizontal distances to the centre of sampling forest inventory plots. Firstly tree DBH and locations were measured with traditional tape measures and Vertex Laser Geo equipment on four permanent circular plots near the Slovenian Forestry Institute. Later the plots were scanned with lidar-equipped Apple iPhone 13 Pro Max. The collected data was analysed with open-source software CloudCompare and R. On average, DBH values from laser scans were 1.49 cm (RMSE = 2.68 cm) greater than reference values, with larger discrepancies for thinner trees. On the other hand, horizontal distances were on average undervalued by 7.1 cm (RMSE = 24.7 cm). Discrepancies in horizontal distances were greater for trees that were measured toward the end of the scanning process, while no such influence of the scanning time was apparent for DBH values.
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