Paula J. Pingree

An FPGA/SoC Approach to On-Board Data Processing Enabling New Mars Science with Smart Payloads

A proposed Mars Scout Mission known as MARVEL is vying for the 2011 launch opportunity. One of its primary instruments, MATMOS, will produce large volumes of data in short, 3-minute bursts during its on-orbit observation of sunrise and sunset. The remaining orbit time of 112 minutes is available for on-board data processing to reduce data volume prior to downlink. This data processing relies heavily on floating-point FFTs. The Xilinx Virtex-II Pro FPGA was evaluated in a previous research task, but could not meet the performance requirements, even with an integrated soft-core floating-point unit (FPU). The next-generation Virtex-4 FPGA contains an auxiliary processor unit (APU) that provides a flexible high bandwidth interface for fabric co-processor modules (FCM) to the PowerPC405 core. In this paper we show that coupling the FPU FCM with the APU provides sufficient computation power to meet MATMOSs data processing requirements when implemented in a multi-processor, dual-FPGA system.

The prototype development phase of the CubeSat On-board processing Validation Experiment

The Xilinx Virtex-5QV FPGA is a new radiation-hardened-by-design (RHBD) part that is targeted as the spaceborne processor for the Decadal Survey Aerosol-Cloud-Ecosystem (ACE) missions Multiangle SpectroPolarimetric Imager (MSPI) instrument12. A key technology development needed for MSPI is on-board processing (OBP) to calculate polarimetry data as imaged by each of the 9 cameras forming the instrument. With funding from NASAs ESTO3 AIST4 Program, JPL is demonstrating how signal data at 95 Mbytes/sec over 16 channels for each of the 9 multi-angle cameras can be reduced to 0.45 Mbytes/sec. This is done via a least-squares fitting algorithm implemented on the Virtex-5 FPGA operating in real-time on the raw video data stream [1]. Last year at this conference the results of a feasibility study between JPL and U. Michigan were presented in a paper titled, “A CubeSat Design to Validate the Virtex-5 FPGA for Spaceborne Image Processing.” Out of that study, a new task has been funded by NASAs ESTO ATI5 Program to integrate the MSPI OBP algorithm on the Virtex-5 FPGA as a payload to the University of Michigans M-Cubed CubeSat, manifest a launch opportunity, and gain on-orbit validation of this OBP platform to thereby advance the Technology Readiness Level (TRL) for MSPI and the ACE mission. This new task is called COVE (CubeSat On-board processing Validation Experiment) and is the topic of this paper. The COVE task is an 18-month effort to develop the flightready U. Michigan M-Cubed CubeSat with the integrated JPL OBP payload. The targeted completion date is September 2011. M-Cubeds primary payload is an OmniVision 2 MegaPixel CMOS camera that will take quality color images of the Earth from Low Earth Orbit (LEO) and save them to a Taskit Stamp9G20 microprocessor. This paper presents the prototype design and integration of the M-Cubed microprocessor system with the JPL payload that provides the image processing platform for on-orbit OBP validation. The high-level requirements and interface specifications for the delivery of the JPL FPGA-based payload hardware to the University of Michigan will be described. Finally, a recent decision regarding a launch opportunity for M-Cubed will be reported.

An evaluation of the Xilinx Virtex-4 FPGA for on-board processing in an advanced imaging system

The multi-angle spectro-polarimetric imager (MSPI) is an advanced camera system currently under development at JPL for possible future consideration on a satellite based Aerosol-Cloud-Environment (ACE) interaction study as outlined in the National Academies 2007 decadal survey. In an attempt to achieve necessary accuracy of the degree of linear polarization of better than 0.5%, the light in the optical system is subjected to a complex modulation designed to make the overall system robust against many instrumental artifacts that have plagued such measurements in the past. This scheme involves two photoelastic modulators that are beating in a carefully selected pattern against each other [1]. In order to properly sample this modulation pattern, each of the proposed nine cameras in the system needs to read out its imager array about 1000 times per second, resulting in two orders of magnitude more data than can typically be downlinked from the satellite. The onboard processing required to compress this data involves least-squares fits of Bessel functions to data from every pixel, effectively in real-time, thus requiring an on-board computing system with advanced data processing capabilities in excess of those commonly available for space flight

Microwave Radiometers from 0.6 to 22 GHz for Juno, A Polar Orbiter around Jupiter

A compact instrument called the MWR (microwave radiometer) is under development at JPL for Juno, the next NASA new frontiers mission, scheduled to launch in 2011. Its purpose is to measure the thermal emission from Jupiters atmosphere at six selected frequencies from 0.6 to 22 GHz, operating in direct detection mode, in order to quantify the distributions and abundances of water and ammonia in Jupiters atmosphere. The goal is to understand the previously unobserved dynamics of the sub-cloud atmosphere, and to discriminate among models for planetary formation in our solar system. as part of a deep space mission aboard a solar-powered spacecraft, MWR is designed to be compact, lightweight, and low power. The receivers and control electronics are protected by a radiation-shielding enclosure on the Juno spacecraft that also provides for a benign and stable operating temperature environment. All antennas and RF transmission lines outside the vault must withstand low temperatures and the harsh radiation environment surrounding Jupiter. This paper describes the concept of the MWR instrument and presents results of one breadboard receiver channel.

Real-time data processing for an advanced imaging system using the Xilinx Virtex-5 FPGA

The multi-angle spectro-polarimetric imager (MSPI) is an advanced camera system under development at JPL for possible future consideration on a satellite based Aerosol-Cloud-Environment (ACE) mission as defined in the National Academies 2007 Decadal Survey. The MSPI project consists of three phases: Ground-MSPI, Air-MSPI, and Space-MSPI. Ground-MSPI is a ground-based demonstration focused on characterizing the imager optics and performance. Air-MSPI will be an updated version of the ground system to be flown on an ER-2 aircraft. Lessons learned from the ground- and air-based demonstrations will be used in the design of the final satellite-based Space-MSPI instrument. In order to capture polarimetric data, the data collection algorithm oversamples the desired spatial resolution by a large factor. The actual polarimetric information can be efficiently extracted from this oversampled data. It has been proposed to do this extraction on the spacecraft for the purposes of reducing the total downlink data rate. As described in [1], the processing can be done in non-realtime on a Xilinx Virtex-4 FPGA. We have shown that this processing can be done in real-time on a Xilinx Virtex-5 FXT FPGA. Pseudo-random data simulating Ground-MSPI data stream is processed on the FPGA and the resulting polarimetric parameters are output using an Ethernet link to a host PC for verification. This demonstration is a stepping stone to an effective implementation for the Space-MSPI instrument.

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 NASAs 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 MSPIs 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. 1,2

Implementing Legacy-C Algorithms in FPGA Co-Processors for Performance Accelerated Smart Payloads

Accurate, on-board classification of instrument data is used to increase science return by autonomously identifying regions of interest for priority transmission or generating summary products to conserve transmission bandwidth. Due to on-board processing constraints, such classification has been limited to using the simplest functions on a small subset of the full instrument data. FPGA co-processor designs for SWM classifiers will lead to significant improvement in on-board classification capability and accuracy. We implemented a SWIL classifier, developed for the Hyperion instrument on the EO-1 spacecraft, on the Xilinx Virtex-4FX60 FPGA as a baseline challenge. We have taken advantage of Impulse Ctrade, the commercially available C-to- HDL tool by Impulse Accelerated Technologies, which supports the development of highly parallel, co-designed hardware algorithms (from software) and applications. This paper describes our approach for implementing the Hyperion linear SVM on the Virtex-4FX FPGA, as well as additional experiments with increased numbers of data bands and a more sophisticated SVM kernel to show the potential for better on-board classification achieved with embedded FPGAs over current in-flight capabilities.

Spaceborne flight validation of NASA ESTO technologies

Small satellites flight experiments, using CubeSats, are growing rapidly as a low-cost and quick turn-around platform for education, focused science observations, and advanced technology validation. This talk will describe recent investments by NASAs Earth Science Technology Office (ESTO) to rapidly advance the TRL of various hardware and software technologies targeted for future Earth Science Decadal Survey Instruments via the CubeSat platform.

Validation of real-time data processing for the Ground and Air-MSPI systems

JPL is currently developing the multi-angle spectro-polarimetric imager (MSPI), targeted for the Aerosol-Cloud-Ecosystems (ACE) mission, as defined in the National Academies 2007 Decadal Survey. In preparation for the space instrument, the MSPI team has built two incremental camera systems (Ground- and Air-MSPI) to improve understanding of the proposed architecture. Ground-MSPI is a gimballed instrument used primarily for stationary observation and characterization of the imager and optics. The ER-2 based Air-MSPI operates in a step-and-stare mode, providing multi-angle imaging of a static target. This mode-of-operation simulates the observation scenario of the space instrument. Physically, MSPI is a pushbroom camera with a specialized frontend. Before imaging, light entering the camera passes through a pair of photoelastic modulators and a set of pattern polarizers. These optical elements act on the light to make polarimetric extraction computationally feasible. Calculating polarimetric parameters from the imagers data stream requires a real-time least-squares computation that produces coefficients of a truncated time-series expansion of the image. As reported in [1][2], the data processing algorithm can operate in real-time on a Xilinx Virtex-5 FPGA. Moving beyond verification with an onboard data source, the algorithm has been validated on a commercial development board interfaced with the ground camera. In addition, the algorithm has been instantiated within the Air-MSPI electronics boards FPGA, and in situ first-light has been achieved.

The Deep Impact Test Benches – Two Spacecraft, Twice the Fun

The Jet Propulsion Laboratorys Deep Impact (DI) Project was a smashing success with its successful Impact and Flyby Encounter on July 4, 2005 (UTC). Deep Impact launched the flight system, consisting of two spacecraft, on January 12, 2005 for an Encounter with comet Tempel 1 just 6 months later. The two spacecraft, known as the Flyby and the Impactor, were separated 24 hours prior to Encounter, whereby the Impactor targeted itself to a collision course with Tempel 1 and the Flyby captured the event as it flew by the comet. Ball Aerospace and Technologies Corporation (BATC) located in Boulder, CO. was the system contractor for the Deep Impact spacecraft. BATC also developed the DI Test Benches. Test benches are developed by a flight project to provide an effective platform for developing flight software and mission sequences, to offload the flight system for pre-launch validation and verification efforts, and to reliably represent the flight system for development and anomaly resolution post-launch. The success of Deep Impact was heavily reliant on these valuable project resources. Developing and operating two spacecraft simultaneously required a unique test bench architecture that could support the various configurations of the DI mission. This paper presents an overview of the Deep Impact test bench architecture. The process and challenges of operating the test benches, specifically in testing Impactor sequences, are described. Lessons learned from the test bench experience on Deep Impact are shared