FPGA Platform for Satellite Observations of VLF Emissions

Poster (Presented at Fall Meeting) (PDF 4.2 MB) Paper Writeup - Current Draft (PDF 166kB)

Submission for Fall 2008 AGU Meeting

Abstract

Transient Luminous Events (TLEs) are unique high-altitude phenomena which have recently been the subject of intense study because they may provide insight into the energy exchange and electromagnetic coupling of the high atmosphere and ionosphere. The systematic observation of TLEs is a difficult problem due to their rare occurrence and low signal levels. Historically, optical observations have been the primary method, and recent research indicates a potential correlation between TLE optical emissions and Very Low Frequency (VLF) radio emissions of a particular signature.

Two opportunities present themselves for unique instrumentation development: first, a low-order "always-on" sensor placed in-situ on board an observational satellite can record all VLF emissions and gather statistical data on the correlation and rate of occurrence of these VLF signatures. Secondly, such a sensor can serve as a triggering mechanism to activate high-fidelity optical instruments to catch the TLE events in real time.

Both of these scenarios present difficult challenges - real-time signal detection requires fast computations; and the space-environment requires both low-power consumption and high resilience to radiation. In light of these constraints, the preferred method is a specialized digital signal processor (DSP) implemented as a Field Programmable Gate Array (FPGA). This technology enables highly parallelizable data processing and due to the specialized hardware specific to this application, power consumption can be reduced. The development of FPGA platforms also offers the capability for extensibility and interoperability with similar ground-stations; additional features such as data recording, user-interfacing, and network connectivity are possible without total system redesign via the FPGA's unique development methodology.

Currently, a hardware prototype has been developed which successfully performs the basic functionality for real-time signal processing and data presentation. Using satellite data from the DEMETER probe, algorithms were designed which could suitably detect the VLF signatures of interest, and these techniques were translated into the FPGA's platform for real-time performance. Systematic benchmarking with this data has verified that the implementation is capable of sustaining high-sensitivity detection, even in noisy environments, by dynamically adapting to the signal environment. This instrument enables statistical characterization of these VLF signatures; further work on the prototype platform will enable rapid delivery and visualization of the scientific data.

Additional Information

TARANIS Algorithm Design Report - 2008-04-01

PDF (2.74 MB)



TARANIS Hardware Prototype Update - 2008-09-21

PDF (513 kB) or PPT (1.24 MB) or PPTX (732 kB)