Abstract: Apparatus for use in a radiation scanning system comprising a radiation detector and an optical system arranged to scan radiation from a field of view across the radiation detector. The optical system includes two sets of planar reflective surfaces, one set being movable relative to the other, and a rotary assembly carrying one of the sets and rotatable about an axis of rotation. The detector is arranged relative to the optical system such that the radiation enters the detector after sequential reflection from reflective surfaces of the two sets, and the surfaces which effect the sequential reflection being separated by a predetermined amount and being located with respect to the axis of rotation such that the angle of incidence of radiation at the detector is independent of the position of the radiation in the field of view.

Abstract: A radiation scanning system which includes a radiation detector located at the focus of an objective lens element and a radiation scanning element arranged to scan radiation emanating from a field of view across the detector. The radiation forms a primary pupil, and one of said elements is located at a conjugate pupil formed by an optical assembly which comprises first and second concave part-spherical reflectors respectively having their centers of curvature substantially optically coincident with the locations of the primary pupil and the conjugate pupil, and a convex reflector substantially coincident with the locus of the focii formed by parallel beams of radiation emanating from the primary pupil and incident upon the first concave reflector.

Abstract: A radiation scanning system comprising a focusing lens which forms an image of radiation received from a field of view and a curved reflector is arranged to reflect radiation onto a plane mirror which is mounted for oscillatory motion about a fixed axis to thereby scan the radiation image. A relay lens is interposed between the plane mirror and a radiation detector and in the plane normal to the axis about which the plane mirror oscillates the radius of curvature of the curved reflector approximates to twice the radius of curvature of the scanned image and in this way the scanned image is presented to the detector at a substantially constant angle.

Abstract: An infra-red scanning system with raster scan display unit operating in the visible spectrum, in which the image is scanned across a linear array of detector elements to provide a signal multiplexer with electrical signals related to the detected radiation pattern. The operation of the raster scan display unit is synchronised to the operation of the scanning system so that the horizontal time base integrator is gated according to the speed of the scanning system, and the vertical time base is gated to operate in synchronism with the multiplexer in order to minimise optical distortion in the display.