A system is described that includes a transmitter for generating a magnetic field comprising a first detection region and a second detection region, wherein the first detection region is different than the second detection region. The system comprises a receiver configured to detect at a location of the receiver in the magnetic field a magnetic field vector, a polarity, and at least one additional vector. The system comprises the receiver configured to use the magnetic field vector, the polarity, and the at least one additional vector to determine a position of the receiver in the magnetic field.