A Procedure for Quantifying a UAV-borne Magnetometer Vertical Setback Distance

Summary Within this study, a vertical buzz test methodology is applied to characterize the distance at which the electromagnetic interference generated by a UAV platform attenuates below the sensitivity threshold of a high-resolution magnetometer in a controlled setting. A DJI Wind 4 heavy-lift, multi-rotor UAV platform was used to characterize the spatial extent of the electromagnetic interference generated inflight. The vertical setback distance of a UAV-borne aeromagnetic system was characterized using a vertical buzz test maneuver in a magnetically quiet area. Through conducting the characterization test, it was determined that the DJI Wind 4 with a 2.2 kg payload required a vertical setback distance of approximately 5 m when surveying with a magnetometer employing a sensitivity of 0.01 nT. Furthermore, it was determined that a magnetometers vertical setback distance is unique for each specific combination of UAV platform and magnetometer employed within a UAV-borne aeromagnetic system. Based on previous tests, using the same magnetometer and methodology, the vertical setback distance was determined to be 3 m, for both a DJI - S900 and M600. Therefore, the assessment shown herein should be conducted to characterize the vertical setback distance for specific UAV magnetometry systems (each platform and magnetometer) prior to conducting surveys.