Evolution of VTEM – technical solutions for effective exploration

Abstract

The helicopter borne time-domain VTEM system has been in constant development since 2002 through complex and multicomponent technical improvements in an effort to satisfy exploration and mining industry requirements. Progress in the geoelectrical informational level of data obtained with different VTEM systems is illustrated with the results of test surveys over the Caber VMS deposit. Forward plate modeling with different systems for the Caber deposit geometry target with changing conductance, as well as resistivity-depth transforms of the real data, both serve to illustrate significant broadening of the conductance aperture and increasing depth of investigation over time. Most of all the increasing sensitivity of the VTEM system is highlighted.

Inversion for 3D Conductivity and Chargeability Models Using EM Data Acquired by the New Airborne TargetEM System in Ontario, Canada

“…This approach facilitates the inclusion of flexible induced polarization (IP) parameterization within the modeling and inversion processes. The simplified GEMTIP model [21] is used, which is similar to the Cole-Cole model [24] and is utilized to parameterize induced polarization effects:…”

“…The aforementioned papers make approximations with the modeling physics, dimensionality, or both to recover a subsurface physical parameter model. Cox et al [10] developed a method of full 3D simultaneous inversion for conductivity and other IP parameters based on the generalized effective medium theory of the IP effect GEMTIP [21]. In that paper, the integral equation (IE) method was used for 3D modeling.…”