Piston phase determination and its effect on multi-aperture image resolution recovery

Multi-aperture coherent LADAR techniques can be applied to generate high resolution images. When setting up a system with multiple sub-apertures, misalignment of the sub-apertures causes the beams entering the sub-apertures to have mismatched optical path lengths, which will degrade the image resolution. Post-processing using image sharpening techniques to correct for piston phase, as well as other aberration corrections, require computing power and time. We study whether the processing time can be shortened by providing measured piston phase information to the image sharpening algorithms. Simulations are used to demonstrate the usefulness of piston phase measurements. Simulations are presented showing the benefits of piston phase measurements for two or more sub-apertures. The speed of convergence for the sharpening algorithm both with and without the piston phase measurements are compared for multiple sub-aperture imaging.