These images demonstrate the possibility of managing image focus regardless of discrepancies between the reference channel and target channel ranges. In the top image, the reference and target channels are carefully matched (see range plot at left). In the lower image, the reference channel path length does not match the target channel path length (net mismatch approximately 1 meter; range to target is approximately 2–3 meters). A digital compensation technique involving a special "sharpness" metric nonetheless produces a well focused image of the triangle target. This image demonstrates that SAIL can employ a fiber-optic reference channel to produce focused two-dimensional images even in cases where the range to target is either uncertain or variable.