MONTAGE Camera as shown at DARPA Tech
Introduction
The MONTAGE (Multiple Optical Non-Redundant Aperture Generalized Sensors) program is sponsored by the Defense Advanced Research Projects Agency (DARPA) under the Microsystems Technology Office (MTO). Program managers are Dr. Ravindra Athale and Dr. Dennis M. Healy, Jr. DARPA's MONTAGE web site notes, “Recent advances in technologies for optical wavefront manipulation, optical detection, and digital post-processing have opened new possibilities for imaging systems in the visible and IR regimes, suggesting the development of imaging systems which differ dramatically in form fit and function from time-honored camera designs. The MONTAGE program seeks to develop and demonstrate truly revolutionary imaging systems obtained by intelligent integration of the advancing capabilities of the individual optical, detection, and processing subsystems. This integration will exploit recent advances in system optimization methods, which provide an emerging capability for co-design and joint optimization of the optical, detection, and processing aspects of imaging systems.”
Folded Optic
Cross section of folded lens.
As illustrated in the figure to the right, the MONTAGE demonstrator's architecture differs significantly from a traditional telescopic camera design. An ultra-thin telescopic lens mounts with a conventional 3 megapixel CMOS sensor integrated as a vertically aligned disk. The diagram of the innovative UCSD folded optic design above illustrates how the 40mm focal length annular aperture lens is compacted to fit within the 5mm thick volume. The aspheric optical element was fabricated in a diamond machined surface on CaF2. In addition, wavefront corrections were applied to one of the optical surfaces to reduce the longitudinal dependence of the point spread function. Using multi-domain optimization (MDO) techniques developed by CDM-Optics a post-processing step improves the depth of field and increases the tolerance to manufacturing uncertainties.
Electronics and System Integration
The platform base houses a dedicated microcontroller and provides USB interconnectivity to additional computing resources. Here at Distant Focus, we designed the electronic circuit boards; developed the firmware, software application interface, and several application components; designed the packaging; and, finally, assembled and tested the combined optical, sensor, and processing system.
This figure shows the sensor board connected to the USB communications board. The sensor board is actually a rigiflex PCB; half rigid and half flex.. |
The assembled MONTAGE camera. This figure shows a closed camera illustrating the finished injection molded enclosure. |
Experimental Results
The following images are created from actual camera data from the non-wavefront coded camera, i.e. the traditional folded design. Since the raw data from the camera was in Bayer format, linear interpolation was performed to create these RGB and monochrome images as the case may be.
Actual image from MONTAGE camera of resolution targets at different depths. This images shows the very small depth of field associated with a camera having an F/# of 0.7. Stopping down the aperture increases the depth of field as in any normal camera. |
Image showing typical color response of the MONTAGE camera. The folded lens was chromatically corrected for the visible and gives very similar results to that of a conventional camera. |
More Information
For additional information regarding the MONTAGE program download this Information Packet or visit the following web sites: