## 4 Discussion  
When conducting repeated measurements, the maximum discrepancy in the results was up to 1 dB. This indicates that the results could vary by as much as 1 dB between different measurements. In all cases, the results of the practical measurements differed significantly from the theoretically presented antenna gain data. This is interesting, because the measurements where performed in a clean environment, and no obvious physical obstruction, weather condition, multipath, or electromagnetic or frequency interference was observed at the UAV's flight altitude. Two-dimensional channel 29 and channel 32 H diagrams at a distance of 200 m from the tower, 235 m height are presented in Figure 17a. Three-dimensional 29 channel 29 and channel 32 H diagrams at a distance of 330 m from the tower (airplane, radii from 190 m to 250 m, step 5 m) are presented in Figure 17b:  
As seen from the provided data, the obtained results varied for different channels and significantly differed from the theoretically presented antenna data. The H-plane radiation pattern plots show how the antenna radiated in the horizontal plane. The directional behavior in Figure 17a indicates variations in radiation intensity around the antenna. A more uniform or expected shape (e.g., circular or smooth lobes) suggests good antenna performance. The 3D plot in Figure 17b shows the radiation pattern in space, helping to visualize coverage at a given height and distance. Irregularities (small fluctuations in red and blue curves) suggest signal variations or potential interference. The red color pattern is symmetrical and smooth, indicating stable radiation and proper design. There are no large distortions or unexpected nulls (areas with weak signals). The radiation coverage was consistent with the expected range. There are significant asymmetries or distortions in the blue pattern, which could mean environmental interference, misalignment, or hardware issues. The signal fluctuated excessively between channels (seen in the red vs. blue differences). The coverage area was too narrow or scattered, reducing effective transmission. The antenna radiation patterns appear mostly stable, but small fluctuations suggest minor variations in propagation. If these variations impact communication quality, further tuning or adjustments might be needed (e.g., modifying positioning, power levels, or interference mitigation). More detailed analysis with additional parameters (e.g., gain, beamwidth, side lobes, and efficiency) would be required, to fully assess the performance. Figure 17: (**a**) Two-dimensional channel 29 and channel 32 H-plane diagrams at a distance of 200 m from the tower. (**b**) Three-dimensional channel 29 and channel 32 H-plane diagrams at a distance of 330 m from the tower (airplane, altitudes ranging from 190 m to 250 m, step of 5 m). The authors defined the following systematic directions for analysis: Measurement Errors, Environmental Interference, Antenna Performance Issues, Experimental Setup and Methodology, and Theoretical Model Limitations. In any case, weather conditions, such as variations in temperature, humidity, and atmospheric pressure, can affect signal propagation. During the experiments, the weather conditions were stable without significant changes. Physical obstructions like buildings, trees, and other structures can cause reflections, diffraction, and scattering of electromagnetic waves. We checked for such conditions and did not find any significant possible interference obstacles. Other electronic devices and communication systems operating in the vicinity can introduce noise and interference. We used a 5.8 GHz communication frequency between the drone and the base station. Harmonics can influence slightly; however, the signal strength from the telecommunication antenna and the drone differ significantly and cannot have great influence. A systematic analysis of each of these factors, including controlled experiments and detailed error analysis, is provided, to identify and mitigate the specific causes of the discrepancies.