The GEM-3 produces inphase and quadrature data at each frequency. Inphase data is sensitive to earth's electrical conductivity and magnetic susceptibility. Therefore, over highly conductive and/or magnetic soil, the inphase data is often too sensitive to sensor height to be a stable detection indicator.

The quadrature data, however, are insensitive to the height variations and, thus, provide reliable detection. The sum of all quadrature data is an excellent detection indicator in magnetic and/or conductive geology.