With the provided 10-feet suspension cables, the magnetic noise due to most commercial drones can be ignored. However, some MagArrow customers experience stability issue, especially in windy conditions.
For a small number of drones, the MagArrow can be attached to the landing gear directly with acceptable noises (line-levelling is still required in data processing).
For most drones, however, this configuration causes too much noise. A half rigid mounting design may solve this problem. It has 2 rigid bars with hinges on one side and 2 flexible cables on the other. On the ground, the rigid side folds to the side. While in the air, gravity will keep the MagArrow further away from the drone. Drone noise can be greatly suppressed since the noise follows 1/R^3. A factor of 2 increase in the separation can lead to a factor of 8 decrease in noise.
Please make sure the hinges and the rigid bars are made of non-magnetic material.
A CAD file of MagArrow can be downloaded here if you want to design such a mounting structure.
Please note that the external helical antenna is NOT in the CAD file.
Great idea. What would be a recommended minimum distance below the drone?
@ellipsis We would recommend the rigid part to be ~ 1m. So with the landing gear, the MagArrow is about 1.5m from the drone.
@rzhang thank you. I’m not sure if I’m reading the CAD file correctly. Is it 27.288 inches between the front and rear eyelets for cable attachments?
@ellipsis You are welcome! From the front of the front eyelets to the rear of the rear eyelets, it is a little more than 27 inches. So, your CAD reading is corret.