A CubeSat design to validate the virtex-5 FPGA for spaceborne image processing
The Earth Sciences Decadal Survey identifies a multiangle, multispectral, high-accuracy polarization imager as one requirement for the Aerosol-Cloud-Ecosystem (ACE) mission. JPL has been developing a Multiangle SpectroPolarimetric Imager (MSPI) as a candidate to fill this need. A key technology development needed for MSPI is on-board signal processing to calculate polarimetry data as imaged by each of the 9 cameras forming the instrument. With funding from NASA's Advanced Information Systems Technology (AIST) Program, JPL is solving the real-time data processing requirements to demonstrate, for the first time, how signal data at 95 Mbytes/sec over 16-channels for each of the 9 multiangle cameras in the spaceborne instrument can be reduced on-board to 0.45 Mbytes/sec. This will produce the intensity and polarization data needed to characterize aerosol and cloud microphysical properties. Using the Xilinx Virtex-5 FPGA platform, a polarimetric processing least-squares fitting algorithm is under development to meet MSPI's on-board processing (OBP) requirements. The Virtex-5 FPGA is not yet space-flight qualified; however, an in-flight validation of this technology on a pre-cursor CubeSat mission is valuable toward advancing the technology readiness level for MSPI and the ACE mission. The Michigan Multipurpose Minisatellite (M-Cubed) is a CubeSat under development by students at the University of Michigan in the Student Space Systems Fabrication Lab (S3FL). The satellite meets the California Polytechnic Institute's (CalPoly's) specifications for a 1U CubeSat. M-Cubed's primary mission objective is to obtain quality color images of the Earth from Low Earth Orbit (LEO). M-Cubed's primary payload is an IDS UI-1646LE-C 1.3 MegaPixel CMOS Camera that will take the images and save them to a Colibri PXA270 Microprocessor. The camera has a resolution of 1280x1024 pixels, each with a size of 3.6 x 3.6 micrometers. This allows for moderate to high-resolution images of the Earth after post-processing. With the current system, there is enough excess volume, power, and mass to support an additional payload. In order for M-Cubed to carry out any additional objectives using other payloads, the attitude, power, mass, volume, and communication capabilities must be compatible. This paper describes the collaborative efforts between the University of Michigan M-Cubed team and JPL's MSPI OBP team to define an integrated CubeSat payload to demonstrate the Xilinx Virtex-5 MSPI OBP algorithm by processing images from the M-Cubed CMOS camera. The outcome of a feasibility study will be described as it pertains to design requirements, payload architecture, interface design, mission objectives, and operational scenarios to advance this collaborative concept toward implementation in 2010. ©2010 IEEE.
