Abstract: A method and apparatus for correcting doppler shifts in synthetic aperture radar data. More particularly, in an optical correlator (10) for synthetic aperture radar data having a means for directing a laser beam (22) at a signal film (12) having radar return pulse intensity information recorded thereon, a resultant laser beam (32) then passing through a range telescope (34), an azimuth telescope (38), and a Fourier transform filter (36) located between the range and azimuth telescopes, thereby forming an image for recordation on an image film (40), a compensation means for doppler shift in the radar return pulse intensity information includes a beam splitter (46) for reflecting the modulated laser beam, after having passed through the Fourier transform filter (36), to a detection screen (48) having two photodiodes (66 and 68) mounted thereon. The photodiodes are positioned on each side of the Gaussian distribution of the Fourier transform spectrum reflected by the beam splitter (46).