Survey design to maximize the volume of exploration of the InfiniTEM system when looking for discrete targets

The manner in which volume of influence varies can be used to determine the optimal design parameters of an InfiniTEM survey. Our analysis reveals that the InfiniTEM system should be operated with a loop separation distance of 1.5 times the loop width (where width and separation are measured parallel to the traverse lines); and that there should be 4 traverse lines between the loops, corresponding to a traverse line spacing of 250 m for a loop width of 1000 m. For the purposes of delineating highly conductive targets, the optimal waveform parameters are a high duty cycle (in our case 0.75), a low base frequency (in our case 10 Hz), and measurements should be made in the B field domain. For the purposes of finding less conductive targets, the base frequency should be high (in our case 30 Hz), the duty cycle should be low (in our case 0.25), and measurements should be made in the ∂B/∂t domain. Our study confirms that the InfiniTEM system can detect a 100 m radius sphere at up to 925 m depth. We have determined that electromagnetic systems are most sensitive to bodies striking perpendicular to the traverse line. As well, we have confirmed that the InfiniTEM system is most effective at detecting vertical targets.