POSITION MEASUREMENT DEVICE AND POSITION MEASUREMENT METHOD

A storage device stores capturing conditions containing a viewpoint position and a shooting direction of the camera (1), model data containing a shape of a segmented mirror, and feature point data representing a positional relationship among a viewpoint position and feature points. A camera (1) captures the segmented mirror having a reflective surface to obtain a captured image containing at least a part of the reflective surface. A marker object (2) has feature points, and is fixed at a predetermined position with respect to the camera (1). A feature-point extracting unit (11) extracts multiple feature points from a captured image when the feature points are reflected in the reflective surface, and determines positions of the feature points within the captured image. A position measuring unit (12) calculates a position of the segmented mirror, based on the capturing conditions, the model data, the feature point data, and the positions of the feature points within the captured image.