Patent ID: 11550034

Abstract:
Provided is a target instrument including a pole, a prism provided on the pole, and a terminal device provided on the pole, wherein the terminal device comprises an image pickup module, a tilt sensor which detects tilts in two axial directions, and an arithmetic control module, wherein the image pickup module acquires an image which includes a reference object, the tilt sensor detects a tilt angle of a target instrument, and the arithmetic control module calculates a tilt direction of the target instrument from a position of the reference object in the image, calculates a tilt direction of the target instrument based on tilt angles in the two axial directions of the tilt sensor, acquires a deviation between the two tilt directions, and corrects the tilt angles in the two axial directions of the tilt sensor to tilt angles in directions parallel to an optical axis of the image pickup module and orthogonal to the optical axis based on the deviation.