Millimeter-wave (mmW) imaging is presently a subject of considerable interest due to the ability of mmW radiation to
penetrate obscurants while concurrently exhibiting low atmospheric absorption loss in particular segments of the
spectrum, including near 35 and 94 GHz. As a result, mmW imaging affords an opportunity to see through certain
levels of fog, rain, cloud cover, dust, and blowing sand, providing for situational awareness where visible and infrared
detectors are unable to perform. On the other hand, due to the relatively long wavelength of the radiation, achieving
sufficient resolution entails large aperture sizes, which furthermore leads to volumetric scaling of the imaging platform
when using conventional refractive optics. Alternatively, distributed aperture imaging can achieve comparable
resolution in an essentially two-dimensional form factor by use of a number of smaller subapertures through which the
image is interferometrically synthesized. The novelty of our approach lies in the optical upconversion of the mmW
radiation as sidebands on carrier laser beams using electro-optic modulators. These sidebands are subsequently stripped
from the carrier using narrow passband optical filters and a spatial Fourier transform is performed by means of a simple
lens to synthesize the image, which is then viewed using a standard near-infrared focal plane array (FPA).
Consequently, the optical configuration of the back-end processor represents a major design concern for the imaging
system. As such, in this paper we discuss the optical configuration along with some of the design challenges and
present preliminary imaging data validating the system performance.