1. A method for determining a current distribution of an object, the method comprising: measuring the magnetic fields in vicinity of the object using a multi-channel measurement device that measures an irrotational and sourceless vector field, whereby one measurement sensor corresponds to each channel; converting a multi-channel measurement signal corresponding to each measurement sensor into signals of a predetermined set of virtual sensors, which signals are mutually orthogonal; and determining the current distribution of the object being measured from the signals of the set of virtual sensors in a predetermined function basis.