Abstract: There is described an improvement of the signal-to-noise ratio of an airborne/ground time-domain electromagnetic apparatus and a measuring/interpretation method for the voltage signal recorded. The system comprises: at least one embedded transmitter-receiver structure with at least one large receiver element allowing low system base frequency excitation and discrimination of targets at depths of at least 1 km; wherein the receiver element is positioned throughout the electromagnetic cavity created by transmitter elements whereas no bucking or suspension means are required; a computer network comprising: a microprocessor, a controller from the microprocessor and a host computer controls transmission of primary magnetic field intensities and reception of secondary magnetic field intensities with least 500 kS/s. A method of interpreting of the voltage recorded by receivers elements based on new sensitivity magnetic kernels is disclosed.