PEKÁROVÁ, TEREZA: Vegetational season impact on spatial accuracy and output quality acquired by remotely piloted aircraft system.[Diploma these] – Technical University in Zvolen. Faculty of forestry; Department of forest management and geodesy. – Thesis supervisor: Ing. Martin Mokroš, PhD. Zvolen: Faculty of forestry, 2019.Today, at a time when technological advances are moving rapidly ahead, innovation and advancement in advancement and development are also coming into the field of forestry. The mapping of the hard-to-reach and dangerous parts of forests by the methods of Earth exploration is a challenging task. Remote sensing techniques can completely or at least partially solve this problem. The breakthrough in this area is UAVs that provide on-demand data and, with their high flexibility, are at the top of other remote sensing techniques. The classic image georeferencing that is obtained with UAVs includes the use of Ground Control Points (GCPs), which greatly reduces the efficiency and benefits of fast mapping in remote areas. The aim of the work was to evaluate the accuracy of real-time kinematics / post-processed kinematics (RTK / PPK) solutions used with UAVs to capture positions using post-processed and corrected measurements by Global Navigation Satellite Systems (GNSS). To compare this solution with GCP-based approaches, the accuracy of the two GCP setting proposals (4 GCP and 9 GCP) was evaluated. We also considered and evaluated other factors affecting accuracy as flight models (combined or individual), type of photogrammetry product (DEM, orthographs and point cloud) vegetation states of stands. We compared RMS errors of positional accuracy and the influence of vegetation and non-vegetation period on one territory, which was horizontally diverse (grass, paths, tree stands and shrubs). I processed the images in AgisoftMetashape Professional. Subsequently, we compared the position of the individual points measured in the field with the positions of the points determined in the images. In this way we determined the RMS error in the horizontal (X and Y) and vertical (Z) directions and the total RMS error. The total RMS error in the vegetation period was 0.118m ≅ 11,8cm; in the non-vegetation period 0.193m ≅ 19cm. At the same time, we compared individual errors using a paired t-test. Based on t-tests we can determine whether the vegetation period had a statistically significant effect on positional accuracy