摘要:
A target employable for three-dimensionally measuring a position and an attitude occupied by an object such as a space craft or the like while the target is attached to the object as well as a system for enabling the object to be three-dimensionally measured from a measuring point remote from the object by using the target are disclosed. The target includes a mark for indicating positions of four or more different points on a single common plane and a spherical reflector of which the center of curvature is located remote from the common plane. In addition, the system includes means for irradiating a light toward the target, image building means for building an image representing the target, image photographing means for photographing the image representing the target, means for extracting from the image representing the target an image portion representing the mark corresponding to the target and image portions each representing a bright point formed by the spherical reflector, means for detecting a coordinate value corresponding to the center of gravity of the image portion representing the mark and coordinate values corresponding to the gravity centers of the image portions each representing the bright point, and means for determining in three dimensions the position and the attitude occupied by the object via a series of calculations based on the aforementioned coordinate values.