A detection and identification system of instruments for use with a surgical navigation system is described. The navigation system contains an instrument assembly containing a coil (of a receiver) having an interior space, an instrument configured to be removably coupled to the coil, and a prong affixed to the instrument and configured to be at least partially disposed within the interior space of the coil when the instrument is coupled to the coil, where the prong has a length corresponding to physical dimensions of the instrument. The navigation system can also contain a transmitter located within the body of a patient. The navigation system can identify interchangeable instruments by providing one or more instruments each having a prong of a length corresponding to the physical dimensions of the instrument, providing a receiver configured to be coupled to the one or more instruments, the receiver having a coil with a depth； and identifying if the one or more instruments is coupled to the receiver based on the length of the prong when the one or more instruments is coupled to the receiver.
