Drone as LoRa® Repeater for Readout of Low-power Sensor Nodes in Precision Agriculture

Precision agriculture requires low-power and ideally wireless underground sensor nodes for monitoring soil moisture, soil temperature as well as chemical soil parameters at the position of the plant roots. LoRa(r) wireless connection offers power-efficient communication at low data rates. We implemented three battery-operated sensor nodes buried at different positions and depths on a field. Due to the soil the sensor signal is heavily attenuated. We investigate the LoRa(r) communication loss at different distances in a hilly landscape. On the one hand, we use a laptop on the ground for readout and loose signal for distances larger than ~300 m. Then we investigate hovering a drone as a LoRa(r) repeater on the field. We demonstrate readout at a distance of ~1000 m with the drone repeater.