# Testing Procedure of Unmanned Aerial Vehicles (UAVs) Trajectory in Automatic Missions
## 2 Materials and Methods-Test Tasks for UAVs and Field Works  
The studies that are discussed in this paper are a significant extension and continuation of the research presented in [40; 41]. The first paper discusses the results of the research that aimed at determining the accuracy of stabilisation of an unmanned aerial system. The tests have been performed for the DJI S900 device with the A2 on-board computer during basic aviation operations. All of the manoeuvres have been performed in the remote control (RC) mode. The position of the UAV has been stabilised by its on-board systems. The first test has been aimed at determining the hovering accuracy by the UAV. It has been divided into two parts that differed in the duration of the measurement (5 min. and 10 min.). The second stage has been aimed at determining the accuracy of the UAV making horizontal and vertical displacements by the predetermined value. The second paper [41] discusses the tests that were conducted in an automatic mode where the basic measurements that are contained in the standards for industrial robots have been performed. The commonly used definition of the UAV for flying devices utilised for the purposes other than recreational or sport ones, says that it is an aircraft that does not require a crew to be present on board and it is unable to take passengers, it is controlled remotely or performs automatic flights. The definition of an industrial robot is as follows: a manipulative industrial robot is an automatically controlled, reprogrammable, multi-purpose manipulation machine with multiple degrees of freedom, having manipulative or locomotive properties, stationary or mobile, for important industrial applications [42]. When considering the above definitions, UAVs can be classified as mobile industrial robots. The paper [41] has analysed the selected tests that are presented in the ISO standard [43] with view to their implementation in the measurements of the UAV positioning accuracy. The works that are discussed there have aimed at verifying the suitability of these standards to examine the UAV positioning accuracy and they have been carried out for one on-board computer An extended set of these tests has also been presented in this paper as task 2 cf. Section 2. The first UAV trajectory tracking measurements were carried out by [PERSON] [44]. An automatic flight trajectory tracker, while using a robotic total station (RTS), has been the first of its kind performed on a UAV system. RTS is a surveying instrument that allows for automatic target search, recognition, and tracking. A test field for UAVs has also been established at the campus of Honggerberg at ETH Zurich. This test field has enabled assess to the flight performance of UAVs. The tests that have been performed in this study have only included the analysis of the accuracy of a photogrammetric mission performed on a small-sized test basis. Basic flight trajectory analyses have been carried out. Similar but more complex tests were described in this paper as task 4 cf. Section 2. In [PERSON] et al. [45], the authors have focused on the analysis of the potential of the positioning accuracy of the UAV system Falcon 8. Consequently, the parameters of the positions, which are also co-determined in the process of direct geo-referencing, have not been considered there. This paper has focused on the comparison of the results from GNSS to direct geo-referencing. In addition, in this paper, the authors have demonstrated that the positioning results using direct geo-referencing have been able to provide information on the accuracy of which a drone can be positioned with. It is lower than what is available while using the prism tracking RTS. Paper [46] provides an alternative method for aerial vehicle localization and control utilising standard construction equipment suitable for onsite fabrication. The three-dimensional (3D) distances between reference and effective flight path have been analysed in order to evaluate the control quality for the RTS guided UAV.