Towards an unmanned airborne platform for electromagnetic geophysical surveying

Numerous applications in exploration geophysics and remote sensing have been proposed for unmanned aircraft systems (UASs), which have less operating cost and risk, as well as the potential to offer data of higher resolution than conventional airborne platforms. Using UASs as platforms for electromagnetic (EM) geophysical surveying is uncommon-magnetics and radiometrics, both passive systems, are overwhelmingly more common as geophysical payload for such aircraft. There are two significant challenges when porting EM methods to UASs: noise and payload mass. A series of noise measurements are shown, which show that interference from the UAS can be avoided by placing the instrument sufficiently far away. To overcome limitations on payload mass and the necessity to minimize noise, a semi-airborne time-domain EM system is proposed where only receiving equipment is flown about a ground-based inductive loop