Extremely-Low Frequency (ELF) Radio Sensing of Unmanned Aerial Systems

This paper describes RF-based detection of un-manned aerial systems (UAS) without using transmit signals. The proposed scheme uses a sensitive magnetometer and digital signal processing algorithm to enable robust detection of high-torque/weig$h$t ratio rare earth magnet-based electric motors that are the enabling technology in electrical UAS. Preliminary experimental results with a 1 $\mathbf{m}^{2}$ receive coil show reliable detection of a small UAS at distances of several meters.