Abstract: Methods, devices and systems for three-dimensional location of the disposition of a sensor coil in a subject including are disclosed. The systems include an array of three or more triplet or quadruplet drive coil sets, at least one moveable sensor coil configured to be disposed in a subject and to provide one or more sensor coil response signals responsive to the respective electromagnetic wave fields, a receiving component configured to control drive signals to the array of drive coil sets and to measure sensor coil response signals from the moveable sensor coil, and a processor is configured to determine a sensor coil disposition in the subject relative to said triplet or quadruplet drive coil sets. The receiving component provides a modified drive signal to maximize or optimize the generated respective electromagnetic wave fields, or the one or more sensor coil response signals.