A system includes a first vehicle having an emitter configured to emit a high RF signal synchronously with at least one EM pulse, and a receiver unit located remote from the first vehicle. The receiver unit includes a magnetic field receiver, an RF transceiver, and a processing module coupled to the RF transceiver and the magnetic field receiver. The receiver unit is configured to receive the high RF signal and the at least one EM pulse from the first vehicle and to determine a proximity of the first vehicle to the receiver unit.