the object angular velocity of the object motion is controlled so that image shift speed is independent of the radial position of the point being viewed an edge detector measures the edge position of the object while the theta theta coordinate stage rotates the object a prealignment process determines position and orientation of the object from measured edge positions a further alignment process uses automated pattern recognition to identify features on the object when the image is rotated so that orientations of the feature are approximately known application_number US 67580703 A description the present invention provides a novel theta theta coordinate stage platform system which removes the linear drive obstruction reduces footprint decreases inspection time decreases cost over both xy and polar stages and improves laminar airflow over the wafer surface in general one rotary axis rotates the object to be inspected while a second rotary axis scans the sensor in an arc across the object surface this method allows for the provision of one or more sensor arms on both the top side and bottom side of the object to be inspected for example fig1 illustrates one embodiment of a theta theta coordinate stage system 10 in accordance with the present invention useful as part of a wafer inspection device in general.