GB1315351A - Method and apparatus for determining co-ordinates - Google Patents

Abstract

1315351 Missile guidance ELTRO GmbH & CO 23 March 1964 [10 May 1963] 12249/64 Heading H4D The invention concerns a method of determining the co-ordinates which an object has in a cross-section of a beam of EM radiation in relation to the axis of the beam. The method is applicable to the control of a flying object being steered along a guiding beam. The beam is produced and transmitted in such a way that any cross-section thereof normal to its axis is an identical projection of the same transmitted image, each component of which providing measurement data corresponding to the coordinates of that component relative to the beam axis. Thus, the co-ordinates of the object in the beam can be evaluated by the object itself from the data. A modulation disc rotating in front of a radiation source produces the image to be projected, components of the image corresponding to values of modulation of the beam and providing the data. In apparatus for performing the method a projector forms a radiation source for image projection. The radiation is bunched and projects the modulation disc, as an image. An optical mirror system projects the image in such a way that each cross-section of the beam contains an identical image. The modulation disc may be circular with transparent slots and opaque webs. If the flying body deviates from the beam axis, the measurement data in the image components are used to provide control signals which are fed to the steering gear of the body. The optical image projection system may contain infra-red filters to allow steering of the body by infra-red. To prevent the flying body from deviating further from the beam axis as it moves away from the launch site the bunching of the radiation is varied. The invention may also be applied to assist the landing of an aircraft when the latter is steered along the beam axis to the landing strip.