Acta Scientiarum Polonorum
Silvarum Colendarum Ratio et Industria Lignaria

Due to the growing potential uses of unmanned aerial vehicles (UAV), a study on their practical application in regenerated openings has been conducted by the Geomatics Section of the Foresters, Science Club, the Poznań University of Life Sciences. In 2019, twenty-one research areas were established in the Murowana Goślina Forest Experimental Station, covering subcompartments 55b and 55j. In the research area there are 110- and 116-year-old pine stands growing in the regeneration class in a group-clear felling system with 40-year-old sessile oak (Quercus petraea (Matt.) Liebl.). The main aim of the study was to compare the measurement potential application of Getac Z710 geodetic GNSS receivers and orthophotomap data provided by the DJI Mavic Pro model UAV. Four (A–D) measuring methods involving the GNSS receiver were used. In measuring methods A–C the GNSS receiver was placed at each boundary corner of the measured opening for 150, 60 and 30 seconds, respectively. In method D the area perimeter was measured by circling them with the receiver set in the “follow” mode. The total area of the measured openings ranged from 1.87 ha to 2.22 ha for subcompartment 55b and 1.22 ha to 1.46 ha for subcompartment 55j. The difference between the results was 0.35 ha and 0.24 ha, respectively. In the case of subcompartment 55b, the result closest to the reference was obtained during measurement method B, while for subcompartment 55j the orthophotomap measurement turned out to be the closest to the reference. The paper also discusses the time intensity of individual measurement methods.