Tracker with switchable radiation characteristics

A tracker, a surgical navigation system with the tracker, and a method of operating the tracker are described. The tracker comprises a first switch configured to be operated between a first switch configuration and a second switch configuration. The tracker also comprises one or more sources of electromagnetic radiation configured to selectively emit electromagnetic radiation with a first radiation characteristic or a second radiation characteristic. The tracker further comprises electrical circuitry configured to selectively control the one or more sources of electromagnetic radiation to emit electromagnetic radiation having the first radiation characteristic in the first switch configuration and to emit electromagnetic radiation having the second radiation characteristic in the second switch configuration, wherein the second radiation characteristic is different from the first radiation characteristic.