Sensor placement can make or break atmospheric measurements from multirotor drones
Multirotor drones can deliver more accurate atmospheric data when unshielded sensors are mounted away from the airframe. A field study of 98 flights found that temperature and water-vapor measurements from small drone sensors depend strongly on where the sensors sit on the aircraft.
The work tested a DJI Matrice 600 Pro hexacopter fitted with iMet XQ sensors that measure pressure, temperature and relative humidity at 1 Hz. Measurements from the drone were compared with readings from an instrumented flux tower and a tethered balloon system carrying identical sensors, which were treated as reference observations. Researchers tested eight sensor positions across the drone during about 15 hours of sampling. The campaign included 82 flights near the tethersonde and 16 flights near the flux tower. Nine flights were conducted at night to separate solar heating effects from errors caused by the multirotor platform itself.
The best results came when sensors were kept away from the drone’s main body and placed in sufficient airflow. A position near, but not directly beneath, a spinning propeller performed best among the tested locations. At that position, daytime temperature errors at the 95% confidence interval ranged from -0.83 to +0.61 K. Nighttime errors were smaller, from -0.28 to +0.48 K. Water-vapor mixing-ratio errors ranged from -0.22 to +0.66 g/kg.
The findings matter as multirotor drones become more common in lower-atmosphere research. Their vertical takeoff, hovering ability, maneuverability and relatively low cost have made them attractive platforms for field campaigns. But many missions cannot carry dedicated radiation shields, ducts or aspirated housings. That constraint is likely to grow with ride-along sensor deployments on drones built for other tasks, including package delivery, and with swarms of mini and micro drones where weight and volume are limited.
The study shows that unshielded sensors are not automatically unreliable, but their placement must be treated as a core design decision. Sensors mounted too close to the central body risk exposure to platform-induced errors, while sensors in better-ventilated locations can produce more useful thermodynamic observations. For UAV operators and atmospheric scientists, the practical implication is clear: careful sensor placement can improve drone-based weather measurements without adding bulky shielding hardware.