3D Imaging Metrology for Space Based Antennas

The MD&T 3D imager is a non-scanning non-stereoscopic camera that captures imagery in 3D. It works by flooding the field of view with sinusoidally modulated infra-red light and then using an image intensifier to demodulate the back-reflected light and amplify its intensity by 10,000X. Consequently, the 3D imager is not light-starved and can capture megapixel 3D images with sub-millimeter accuracy over hundreds of meters of range. Nonetheless, the current embodiment has several limitations that preclude its use in real-world applications. These limitations, such as off-board processing, overheating, poor SWaP performance, and eye-safety concerns, are each addressed in the proposed Phase II project. The first half of the project entails the integration of an off-the-shelf Kria K26 FPGA/Arm processor which will perform the on-board processing function. This work, performed by sub-contractor D3 Engineering, includes the design of a custom carrier circuit board, which will interface the K26 to the rest of the camera, as well as FPGA firmware and Arm® software coding. The mechanics of the earlier versions of the 3D imager were laid out in an ad hoc manner resulting in a camera that was overly large and prone to overheating. These problems will be corrected in the Proposed Phase II project by sub-contractor LightForce Technology wherein the camera’s mechanics will be professionally engineered. Importantly, no cooling fans will be utilized as convection cooling is not an option for space-based equipment. Other Phase II work entails the redesign of the imager’s remaining circuit boards for improved performance, reduced power consumption, and reduced size and weight. An analysis of several retro-reflector types will provide insight into which retro device provides optimal antenna structure metrology. An analysis of the infrared emissions will seek to eliminate any ocular hazards associated with the camera.  In the final stages of the project, a medium-sized truss-based structure will be constructed from 1” PVC piping, outfitted with a series of retro-reflectors, and then 3D images of the structure’s retro-reflectors captured. Next, the structure is manually deformed by a known amount and then additional 3D images of the retro’s are captured. A comparison is then made in software between the two sets of imagery and the difference in shape of the structure is mathematically determined and compared against the known deformation. This work will serve to prove the performance of the 3D imager in a close-to-reality configuration. The PI for the proposed project will be Mr. James Munro, the inventor of the 3D camera. Jim holds BSEE, MS Optics, and MBA degrees as well as 40 US patents. Mr. Munro is also a reviewer for 3D imaging and photogrammetry papers for SPIE’s Journals of Electronic Imaging and Journal of Optical Engineering. All proposed work will be performed at MD&T facilities in Ontario, NY.