STAR TRACKER WITH BAFFLE

A star tracker is used to measure the direction of stars. Preferably a wide imaging range is provided so that a reliable orientation of the star tracker can be computed from measurements of the directions of star at substantially different directions. The star tracker comprises a light baffle and located between the light baffle and an image sensing arrangement. The light baffle comprises an array of walls, including sidewalls and at least one internal wall between the sidewalls. Preferably, the side walls and the at least one internal wall are oriented at mutually different orientations emanating from a virtual line of intersection of the planes of the walls. Thus a range of star directions can be imaged with constant sensitivity.