Testing and Assessment of Small Unmanned Aerial Vehicle Susceptibility to Environmental Radio Frequency Interference

Electromagnetic compatibility is a crucial factor to consider for reducing potential safety concerns while designing and operating unmanned aerial vehicles (UAVs). Radio frequency (RF) signals transmitted by nearby electronic systems, such as Wi-Fi hotspots or cellphone and television broadcast base stations, may interfere with a small UAV's command and control (C2) links, subsystems, and sensors. The interference comes through communication pathways or coupling of the RF electric field. We conducted various tests using two different UAVs to assess the impacts of radio frequency interference (RFI) on their functionality and operational safety. We used software-defined radios to generate RFI signals spanning from 60 MHz to 6 GHz. We established the signal-to-noise ratio thresholds for stable, unstable, and disrupted C2 link connections for both models operating at 2.4–2.5 GHz and identified in-band and adjacent-band RFI scenarios in which the C2 links of one UAV model may be disturbed. We also discovered that RFI signals emitted at very high frequency (VHF) bands utilized by television broadcasting channels had adverse effects on both UAVs. We identified the VHF bands and electric field strengths that adversely affected the UAV's C2 link connection and compass. We conducted flight and shielding experiments to further confirm our findings, and finally, we provide recommendations for reducing the UAV's vulnerability to RFI.