Abstract: Method for no-contact measurement of the relative velocity, position, or displacement path of objects without special optical markers with respect to a reference position in at least one coordinate direction, or of the degree of image quality of an image wherein the apparatus images the object on a grating and the light fluxes leaving this grating are measured by means of photoelectric elements. The output signals of the photoelectric elements exhibit a frequency component proportional to the velocity of travel. The present invention is distinguished from the prior art by having a physical beam splitter (6,13) inserted in the imaging beam path in front of the grating (5,14), and preferably several polarizing beam splitters (7,30-33) with at least respectively one associated photoelectric receiver pair (10,11,16-19 16'-19') are connected after the grating (5,14).

Abstract: Means for stabilizing the line of sight between an object and an optical viewing system which can move relative to each other, characterized in that electrical signals are derived with the aid of an optical grating (3',3") as a correlator, which signals correspond to the deviation from the line of sight (4) with respect to magnitude, direction, and arithmetic symbol; and that these signals are fed to a follower system (11,12) such as disclosed in L. M. Biberman: Reticles in Electro-Optical Devices, Pergamon Press, 1966, p. 45 which displaces the line of sight (4) until the original condition has been restored and the deviation has become zero again.