METHOD OF UPDATING CALIBRATION DATA AND METHOD OF MANUFACTURING DEVICE

PROBLEM TO BE SOLVED: To realize position detection with high long term stability without being affected by changes in refractive index of a medium.SOLUTION: The method of updating calibration data of a first position detection system configured to determine the position of an object is presented. The first position detection system includes a target and a plurality of sensors one of which is mounted on the object and the calibration data including coefficients relating an apparent measured position to an actual position and which can be used to convert the apparent measured position to the actual position thereby to correct for physical imperfections in the first position detection system and enable determination of the actual position from the apparent measured position.