Ok, This caught my eye and besides looking cool I'm sure it has some practical applications especially for wide area surveys. Anywho, Geotech Ltd can apparently do airborne geophysical surveys including, resistivity, gravity, magnetic and apparent conductivity. They use a time domain electromagnetic system or VTEM (i don't understand the acronym either) which allows them to get
"deep penetration, high spatial resolution, excellent resistivity discrimination, and detection of weak anomalies"If anyone can understand their highly technical website and tell us what it can do for geotechnical investigations, please feel free to comment.
PS. The acronym stands for Versatile Time-domain ElectroMagnetics