Diffraction Diffraction occurs at the edges of optical elements and field stops, this limits the Field-of-View(FOv) This is THE limiting factor, which causes spreading of screen J=IEl light and limits the"sharpness u of an image 入 pinhole u=-bsin e Incoming light B Intensity B-aperture sIze 0-angle of boresight pattern Fraunhofer diffraction Thoery (very distant object) is applied sine function is replaced by J, for a circular aperture Chart: 9 February 13, 2001 16.684 Space Systems Product Development MIT Space Systems LaboratoryDiffraction Diffraction occurs at the edges of optical elements and field stops, this limits the Field-of-View (FOV). This is THE limiting factor, Intensity T 2 §sin u · which causes spreading of screen I E Io ¨ ¸ light and limits the “sharpness © u ¹ of an image” O pinhole S u BsinT O Incoming light B B - aperture size T - angle of boresight pattern Fraunhofer Diffraction Thoery (very distant object) is applied. sine function is replaced by J1 for a circular aperture Chart: 9 16.684 Space Systems Product Development MIT Space Systems Laboratory February 13, 2001 2