The invention relates to a handheld measuring aid for use in a system having a station for determining the position and orientation of the measuring aid, the handheld measuring aid for surveying an object surface. The measuring aid has a body and visual markings disposed in a defined spatial relationship, forming a pattern, on the body in a marking region. In addition, the measuring aid has a connection for receiving a measuring, inspection or processing tool, wherein the connection has a joint, such that the tool is pivotable or rotatable in at least one direction. Furthermore, the connection or tool has a position encoder for determining the rotational position of the joint or tool.