A medical tracking system comprising at least two sensor devices which are independently maneuverable and can be positioned in a fixed position relative to targets, each sensor device comprising at least a marker device and a marker device detector for determining sensor data representing the position of the marker device of another sensor device, the system further comprising a control unit configured to receive and combine the at least two sensor data of the at least two sensor devices in order to determine a relative position between at least two of the at least two sensor devices.
