Figure 4. Imaging and reconstruction of 1951 USAF resolution target for group 2 and 3.
(a) Object reconstruction at various depths, when the target was positioned at a depth of 18 mm, 18.64 mm, 19.27 mm, 19.91 mm, 20.54 mm, and 21.18 mm. The best reconstruction corresponding to the actual target depth is labeled by a red dashed boundary. No background suppression was employed for this 2D sample. (b) Zoom-in view of the best reconstruction of target at 18 mm depth, and the line profiles of the horizontal line pairs and vertical line pairs of group 3, element 2.