Method and apparatus for photoelectrically determining the position of

Abstract

Method and apparatus for measuring distance using an optical correlator system containing at least one imaging optic, at least one optically active array, and at least a system of photoelectric detectors associated with the array preferably in the form of an optical grating structure wherein for the purpose of unambiguous distance or range determination by means of optical-geometric steps in the image region and/or in the Fourier space, different beam guidance systems are constructed so that for axial relative motion between object image and array output signals are generated at each photoelectric detector system associated with each beam guidance system, these output signals differing among themselves in frequency and hence (also) in phase. A comparison is made of the output signals and from the comparison the geometric image position of the principal maximum is determined with respect to the geometric positions of the secondary maxima.