Universal wavefront sensor apparatus

Claim 1

A wavefront sensor apparatus for a large optical system comprising in combination: an optical system utilizing an objective lens to form an image of a ground scene at the focal plane of said optical system, a reticle means positioned at the focal plane of said optical system to select a scene spatial frequency from said image at said focal plane, a field lens to form an image of the objective lens, an array of sensors to receive said objective image, said array of sensors comprising a predetermined number of sensor cells, each sensor cell of said array of sensors receiving a portion of said image, means for providing relative linear non-periodic motion between said ground scene and said reticle means to provide an image signature to all cells in the array, and an electrical circuit to measure time differences between the respective image signatures to determine relative image displacements caused by wavefront slope error, wavefront slope errors are the variations in slope among the different sections of the wavefront.