Abstract: Imaging apparatus is disclosed for passive microwave, millimetre wave, sub-millimetre wave or infrared imaging, the apparatus including a receiver (10) for receiving radiation from the scene or subject being imaged, means for directing such radiation onto the receiver, a cold source (16) or a hot source (16), i.e. a source with a low or high black body temperature, and means (14, 14a) for directing the image or shadow of said cold source or hot source onto the scene or subject being imaged. The result is to produce improved contrast in the image obtained.

Abstract: A scanning apparatus comprises two rotatable bodies (1,10 or 40) arranged to rotate in opposite directions. The first body being a polarizer (10) and the second being a mirror (1) or a second polarizer (40). The apparatus is arranged to define an optical path for a polarized beam, wherein the optical path passes through the first body (10), is reflected at the second body (1 or 40), and is reflected by the first body (10) back to the second body (1 or 40) from where it is transmitted or reflected to produce a linear scan. There is also disclosed a scanning system comprising a reflector (1) and an optical wedge (42) containing refractive materials, arranged to counter rotate and arranged so that a beam passing through the optical wedge (42), is reflected by the reflector (1) and passes back through the optical wedge (42) to produce a linear scan.

Abstract: A scanning apparatus comprises two rotatable bodies (1, 10 or 40) arranged to rotate in opposite directions. The first body being a polarizer (10) and the second being a mirror (1) or a second polarizer (40). The apparatus is arranged to define an optical path for a polarized beam, wherein the optical path passes through the first body (10), is reflected at the second body (1 or 40), and is reflected by the first body (10) back to the second body (1 or 40) from where it is transmitted or reflected to produce a linear scan. There is also disclosed a scanning system comprising a reflector (1) and an optical wedge (42) containing refractive materials, arranged to counter rotate and arranged so that a beam passing through the optical wedge (42), is reflected by the reflector (1) and passes back through the optical wedge (42) to produce a linear scan.

Abstract: A scanning apparatus comprises two rotatable bodies (1, 10 or 40) arranged to rotate in opposite directions. The first body being a polarizer (10) and the second being a mirror (1) or a second polarizer (40). The apparatus is arranged to define an optical path for a polarized beam, wherein the optical path passes through the first body (10), is reflected at the second body (1 or 40), and is reflected by the first body (10) back to the second body (1 or 40) from where it is transmitted or reflected to produce a linear scan. There is also disclosed a scanning system comprising a reflector (1) and an optical wedge (42) containing refractive materials, arranged to counter rotate and arranged so that a beam passing through the optical wedge (42), is reflected by the reflector (1) and passes back through the optical wedge (42) to produce a linear scan.

Abstract: An apparatus for redirecting radiation including a polarization dependent reflector and an optical component able to transform the polarisation of radiation as it passes through the component. Radiation having a first polarisation component impinging upon the reflector from a source is reflected towards a scene area. Radiation not having this polarisation component passes through the reflector. The radiation having the first polarisation is then transmitted towards a scene via the optical component. As the radiation passes via the optical component, reflects back from the scene and passes again via the optical component, the polarisation is changed to state where it can now pass through the polarisation dependent reflector. The apparatus allows a scene to be illuminated as if the illuminator were positioned at the viewpoint of an imaging system, and so aids uniform illumination of the scene.

Abstract: Scanning apparatus operable in the microwave, mm-wave and infrared ranges and comprises a support structure, a first reflective disc or mirror (10) which is mounted in said support structure for rotation relative to the support structure about a first axis (14), and a second reflective disc or mirror (12) which is mounted in said support structure for rotation relative to the support structure about a second axis (16) and driving means for said discs or mirrors arranged to drive these in respective opposite senses. In operation of the apparatus, radiation from a scene being scanned reaching a reflective surface of the first disc or mirror is reflected thereby onto a reflective surface of the second disc or mirror, to be reflected by the latter, in turn, onto the reflective surface of the first disc or mirror again, to be reflected from the first disc or mirror into or onto a further part of the apparatus incorporating a receiver or receivers for such radiation.

Abstract: A scanning apparatus comprises two rotatable bodies (1, 10 or 40) arranged to rotate in opposite directions. The first body being a polariser (10) and the second being a mirror (1) or a second polariser (40). The apparatus is arranged to define an optical path for a polarised beam, wherein the optical path passes through the first body (10), is reflected at the second body (1 or 40), and is reflected by the first body (10) back to the second body (1 or 40) from where it is transmitted or reflected to produce a linear scan. There is also disclosed a scanning system comprising a reflector (1) and an optical wedge (42) containing refractive materials, arranged to counter rotate and arranged so that a beam passing through the optical wedge (42), is reflected by the reflector (1) and passes back through the optical wedge (42) to produce a linear scan.