Abstract: An imaging method and associated system for producing high-resolution images. The method includes illuminating an object or scene with coherent radiation such as beams from a laser and then, collecting scattered light with a plurality of subapertures rather than a single large aperture. The method continues with coherently detecting, such as with heterodyne detection, the scattered light to measure the complex amplitude incident on each subaperture and digitally reconstructing images from the coherently detected light for the subapertures. Then digital co-phasing is performed on the subapertures using an image sharpness or quality metric to form an image having the resolution of the total subaperture area. The method may also include determining an aimpoint in the formed image, calculating a phase screen, directing laser beams through the subapertures towards the aimpoint, and co-phasing the laser beams by applying the phase screen to form a single beam.

Abstract: An apparatus for indicating misalignment of the optical elements of an optical system (10) comprises a source (11 ) of optical radiation (which is in general nonpolarized), a beam splitter (12), an optical flat (13) and an off-axis beam sampling device (14). The beam splitter (12) divides an input beam (20) from the source (11) into a transmitted component (21) which passes along the optic axis of the optical system (10) to the optical flat (13), and a reflected component (22) which passes to the off-axis beam sampling device (14). The beam sampling device (14) divides the reflected component (22) of the input beam (20) into two angularly separated beams (24) and (25), which are returned to the beam splitter (12). The beam splitter (12) transmits components (24') and (25'), respectively, of the angularly separated beams (24) and (25) to a detector plane (23).

Abstract: A complex optical system may be maintained in alignment by means of a technique in which an analytical model of the system is utilized which is assumed to be capable of essentially optimal performance. A physical example of the same system design is then assembled and a plurality of performance characteristics are measured related to the intensity function associated with a point source image on the system's focal plane detector array. A plurality of specific adjustments are then calculated by means of a second order approximation technique which would have the effect of degrading the performance of the analytical model to equal that measured for the physical example, whereupon compensating physical adjustments are made to the physical example to improve its measured performance.

Abstract: A complex optical system may be aligned by means of a technique in which an analytical model of the system is utilized which is assumed to be capable of essentially optimal performance. A physical example of the same system design is then assembled and a plurality of performance characteristics measured. A plurality of specific adjustments are then calculated which would have the effect of degrading the performance of the analytical model to equal that measured for the physical example, whereupon compensating physical adjustments are made to the physical example. For many applications, the performance measurements may relate to aberrations to the wavefront of the point source image quantified by means of a Hartmann mask or the like. In that event, the estimation technique may be a straight-forward linear approximation technique including possible damping and/or weighting factors.