Abstract: An opto-electronic device for detecting a beam of radiation and determining the angle-of-arrival of that beam with a high degree of angular resolution. The device has a linear array of radiation detectors arranged in a plane with a shadow mask located at a predetermined height h above and parallel to that plane wherein the shadow mask has a plurality of transparent apertures separated by opaque areas. Each radiation detector in the array comprises at least one pair of individual detector elements and apertures of the shadow mask, which apertures have the same width as the detector elements, are centred directly above the area between adjacent detector elements. Signals generated by corresponding detector elements in each radiation detector are supplied, in parallel, to one channel providing a number of output channels which correspond to the number of individual detector elements in each radiation detector.

Abstract: An apparatus for detecting a beam of radiation, such as a collimated laser beam, and determining the angle-of-arrival of that beam with a high angular resolution, the apparatus comprising a linear array of radiation detectors arranged in a plane and a digital Gray code shadow mask, located at a predetermined height above and parallel to the plane. The Gray code shadow mask is provided with parallel rows containing slot(s) with each of those rows being centrally positioned directly above one of the radiation detectors and arranged so that the rows are perpendicular to the linear array. The slot(s) in each row are located at predetermined distances from the center of a row with those distances differing for each row. A well collimated radiation beam, such as from a laser, directed towards the shadow mask will project images of the slots onto the plane with the positions of the images being dependent on both the positions of the slots and the angle-of-arrival of the beam.

Abstract: An identification friend-or-foe system for vehicles wherein each vehicle is provided with a radiation transmitter and a receiver with a detector for detecting radiation transmitted by other vehicles. Each transmitter can transmit a first coded signal which can be detected by the receivers in other vehicles, the receivers providing an unblocking signal after the first coded signal is correctly identified. The unblocking signal clears a radiation transmission path in the vehicle, the path containing a reflector which reflects the received signal back to the source of the transmission. The reflector adds a further predetermined code to the signal reflected from the reflector with each vehicle having another detector for detecting a reflected signal and a device to identify the further predetermined code.

Abstract: A recording system for use with a laser weapon simulator in which a laser am is transmitted through a window, bearing a target visible to the marksman, and onto a film record. A filter in the window blocks passage of the ambient light but passes the light from the laser beam and the back face of the window is provided with an illuminated, generally superimposed replica of the target. The replica of the target is photographed at the instant of firing by means of a camera, the shutter of which is electronically coupled to the weapon simulator, thereby permanently recording the position of the laser hit.