A Novel Lightweight Dual-Drone Transient Electromagnetic System with Offset Geometry for Near-Surface Mapping

Summary This paper introduces a lightweight dual-drone transient electromagnetic system developed in response to the rapidly growing drone applications in near surface geophysics . Drones are now widely used in geophysical surveying, however, the use of transient electromagnetic sensing on commercially available lightweight drones has so far remained challenging to develop. To address this gap, we present a dual-drone TEM concept designed for rapid and flexible subsurface mapping. By distributing the transmitter and receiver across two commercially available drone, the proposed configuration enables practical deployment within lightweight drone classes. The system employs an offset geometry, with the transmitter and receiver carried independently, allowing operation within strict payload limitations while preserving measurement performance. The system is designed to investigate depths ranging from the first few meters to 100–150 meters, depending on geological conditions. It uses dual-moment transmission, early-time signal acquisition, GPS-based synchronization, and continuous tracking of key geometric parameters. These include the transmitter-receiver offset, measured independently of the drones, and continuous altitude measurements from both platforms. Incorporating these parameters into the workflow enables real-time data inversion and improved interpretation during field operation. The conference presentation will include system validation, flight test results, survey performance, and a real-world mapping example.