# Testing Procedure of Unmanned Aerial Vehicles (UAVs) Trajectory in Automatic Missions
## 3 Results
### Task 1--Determining the Hovering Accuracy by the UAV
In the case of the vertical drift, it has occurred in all tests and, specifically, the values for each on-board computer have been similar regardless of the weather conditions. At the same time, the calculated values of the drifts for the data that were captured from the both on-board computers (LOG data) are close to zero, failing to identify such an error, which clearly indicates their inaccurate operation. \begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline  & & & \multicolumn{3}{c}{**PROJ-MS50**} & \multicolumn{3}{c}{**PROJ-LOG**} & \multicolumn{3}{c}{**MS50-LOG**} \\  & & & **N [m]** & **E [m]** & **A [m]** & **N [m]** & **E [m]** & **A [m]** & **N [m]** & **E [m]** & **A [m]** \\ \hline \multirow{6}{*}{LIGHT WIND} & MAX & 1.85 & 1.93 & 2.31 & 0.80 & 0.94 & 0.66 & \(-\)0.03 & 0.30 & \(-\)0.23 \\  & & MIN & 0.11 & \(-\)0.56 & 0.49 & \(-\)0.63 & \(-\)1.28 & \(-\)0.97 & \(-\)1.59 & \(-\)2.11 & \(-\)2.37 \\  & COM-1 & MAX-MIN & 1.74 & 2.49 & 1.82 & 1.42 & 2.22 & 1.63 & 1.55 & 2.41 & 2.14 \\  & & \(\overline{X}\) & 0.78 & 0.94 & 1.32 & \(-\)0.02 & 0.08 & \(-\)0.05 & \(-\)0.80 & \(-\)0.87 & \(-\)1.37 \\  & & \(\sigma\) & 0.30 & 0.48 & 0.36 & 0.25 & 0.42 & 0.28 & 0.25 & 0.41 & 0.40 \\ \cline{2-11}  & & MAX & 2.15 & 1.54 & 5.57 & 0.64 & 1.00 & 1.09 & \(-\)1.24 & \(-\)0.20 & \(-\)3.23 \\  & & MIN & 1.06 & \(-\)0.29 & 2.81 & \(-\)0.42 & \(-\)0.80 & \(-\)1.29 & \(-\)1.85 & \(-\)0.72 & \(-\)4.76 \\  & COM-2 & MAX-MIN & 1.10 & 1.82 & 2.75 & 1.06 & 1.81 & 2.38 & 0.61 & 0.52 & 1.53 \\  & & \(\overline{X}\) & 1.66 & 0.77 & 3.93 & 0.11 & 0.32 & \(-\)0.08 & \(-\)1.55 & \(-\)0.45 & \(-\)4.01 \\  & & \(\sigma\) & 0.23 & 0.35 & 0.65 & 0.22 & 0.35 & 0.54 & 0.11 & 0.12 & 0.37 \\ \hline \multirow{6}{*}{STRONG WIND} & \multirow{6}{*}{COM-1} & MAX & 2.60 & 1.62 & 3.86 & 0.79 & 0.86 & 0.74 & 0.62 & 1.60 & \(-\)2.38 \\  & & MIN & \(-\)0.40 & \(-\)0.85 & 2.39 & \(-\)0.86 & \(-\)1.07 & \(-\)0.60 & \(-\)2.80 & \(-\)2.02 & \(-\)4.17 \\  & & MAX-MIN & 3.00 & 2.47 & 1.47 & 1.66 & 1.93  
The results for COM-2 present drift in horizontal position, even in light wind, which increases in stronger wind. Vertical drift for COM-1 is independent of wind force, but for COM-2 drift is much higher in strong wind. The performed test will allow for checking the possibility of the use of UAVs in specific missions that require flights with small horizontal and vertical separations. This effect could be very dangerous in urban environments, e.g., when mapping a building, it is very likely, that the UAV is flying close to infrastructure, which is blocking, diffracting, or reflecting GNSS signals. These effects are called site-dependent GNSS effects [29]. For example, in [50], it was shown that deviations of 10-100 m have to be expected during a GNSS outage of 30 s, when MEMS inertial sensors are used on a UAV. However, in the paper on the control of a UAV with a RTS, the following results are achieved for the 3D control quality--a Root Mean Square Error (RMS) of 329 mm was detected for the complete flight path [46]. The horizontally projected evaluation of the control quality, referenced to the x-y plane, revealed a RMS of 104 mm and the vertically projected evaluation, referenced to the y-z plane, indicated a RMS of 319 mm. In this case, the working space was also limited to a very small space.