Implications on EM Exploration Derived from HEM Sea Ice Thickness Research

Helicopter EM for sea ice thickness profiling represents a geophysical situation different from classic exploration targets, allowing further in sight into the HEM method from an unorthodox point of view. The uncommon geometry of the small bird and low altitude as well as the high conductivity of the ocean water arise different results than in conventional airborne EM. Some of those aspects are mentioned in this paper focusing on a more detailed footprint description, the relationship between sensitivity, instrument noise and precision and consequently the delicacy of formal 1D inversion when the target accuracy is in the cm range.