Patent ID: 7857703

Claim:
A method for coordinate generation to be implemented using an orientation device, which is provided with a sensor that has an optical axis, said method comprising the steps of: A) providing at least three reference marks on a target that defines a first coordinate space; B) aiming the orientation device at an initial point on the target, and operating the orientation device such that the sensor is able to capture an image of the target that contains at least one of the reference marks, wherein one of the reference marks serves as the initial point; C) from the image captured in step B), determining an axis correction value, which is an offset of the optical axis of the sensor from an axis of the orientation device; D) aiming the orientation device at a target point on the target, and operating the orientation device such that the sensor is able to capture an image of the target that contains the reference marks and that defines a second coordinate space; and E) determining coordinates of the target point on the first coordinate space of the target with reference to the axis correction value and a relation established between the first coordinate space of the target and the second coordinate space of the image captured in step D), wherein step E) includes: E1) determining coordinates of the reference marks on the second coordinate space of the image captured in step D) and assigning each of the corners of the target with coordinates on the first coordinate space of the target; E2) performing planar projective transformation calculations upon the coordinates of the reference marks determined in sub-step E1) and the coordinates of the corners of the target assigned in sub-step E1) to obtain a first transformation matrix; E3) determining the coordinates of the target point on the first coordinate space of the target with reference to the first transformation matrix obtained in sub-step E2) and the axis correction value determined in step C).