Multicopters for Geophysical Research

The current paper presents three multicopters developed at the Space Research and Technology Institute – Bulgarian Academy of Sciences. These unmanned aircraft designs are aimed at geophysical research and are particularly usable for detection of objects on ground surface and underground. The detection is realized by taking advantage of certain objects' properties. Metals and other conductors are identified by their electrical conductivity. Ferromagnetic objects are discovered by observing their magnetic permeability. Voids and other objects are localized utilizing the difference of the dielectric permittivity that is encountered on the boundary of the object and surrounding ground or rock. Some of the potential targets discoverable with the described geophysical drones are military land mines (including anti-personnel and anti-tank mines), ammunition depots, reservoirs, pipelines, underground galleries, voids, bunkers, tunnels, etc. All three developments are subject to patent protection.