Astronomical, particularly solar and/or lunar, goniometric indicator

摘要

An astronomical, particularly solar and/or lunar, goniometric indicator comprising a reflecting member (1; 16; 20) having at least one planar surface scored with substantially circular and concentric microgrooves, wherein the width and the depth of each microgroove and the distance between adjacent microgrooves are adapted to let a diametral line of diffracted and/or reflected light appear when the at least one planar surface is illuminated by a light source, the reflecting member (1; 16; 20) having at least one orientation line (2, 17) that is radial with respect to the microgrooves.