UAV-Based Environmental Magnetic Field Measurement Method Using a TMR Sensor

Newly built high-voltage sites are required to assess their impact on the environmental magnetic field (MF), and surveyors mainly conduct on-site measurements on foot. However, the measurement process often encounters the problem of harsh on-site environment, the measurement method is limited, and the evaluation results may be questioned. This study proposes a new environmental MF measurement method based on tunneling magnetoresistance (TMR) sensors. In this method, the designed TMR-based MF sensor is mounted on an unmanned aerial vehicle (UAV) to realize large-area and remote MF measurements. All the sensing signals are acquired and processed by the embedded system on the UAV. In addition, the UAV is equipped with a GPS antenna and Wi-Fi wireless communication. All the fundamental and harmonic components of the MFs obtained through signal processing are marked by the GPS satellite time and position. Subsequently, all data are wirelessly transmitted to the environmental MF monitoring platform via Wi-Fi for real-time display and storage. The study also evaluates the electromagnetic field interference of the UAV with the designed MF sensor to determine possible errors in the MF measurement results and make corrections. Finally, experiments are conducted using seven different MF components to evaluate the accuracy of the proposed environmental MF measurement technique. Moreover, an actual field measurement is conducted to verify the feasibility of the proposed method for the environmental MF measurement.