In one embodiment, a radar is provided that is configured to construct an
image of a target within or adjacent to a substrate according to scan
points associated with a surface of the substrate while the radar is
scanned in a first direction. The radar includes a transceiver that
transmits radar pulses and receives reflected radar pulses using an
antenna directed at the surface; and an image processor configured to use
a plurality of processed received radar pulses to generate an image
portion according to each scan point; and at least one laser range finder
being configured to illuminate a first surface portion within a surface
portion illuminated by the antenna and to illuminate a second surface
portion displaced in the first direction from the first surface portion,
the laser range finder determining a first range between the laser range
finder and the first surface portion and determining a second range
between the laser range finder and the second surface portion, wherein
the radar is configured to process the first and second ranges to
determine a range translation of the radar during the scan in the first
direction, and wherein the image processor is further configured to
compensate the image portions according to the determined range
translation so at construct an image of the target.