Determination of Plasmaspheric Electron Densities from IMAGE RPI Dynamic
Spectra using a Semi-Automated Fitting Technique

Phillip Webb


This talk will describe the development of a semi-automated technique to
estimate the cold electron plasma frequency (fpe) of the plasmasphere and
plasmatrough from dynamic spectra obtained by the RPI instrument on the
IMAGE satellite. The electron density (Ne) can then easily be found, since
Ne J fpe2. With approximately 3 1/2 years of data to date (as of October
2004), and the mission ongoing, the 14-hour orbit of IMAGE has resulted in
approximately 4000 separate inbound and outbound dynamic spectra. A fitting
method has been developed that considers physical features found in the
dynamics spectra, such as the upper-hybrid band, the continuum edge, and
n+1/2 emissions. This semi-automated method will allow the dynamic spectra
to be fitted in a timely manner to determine Ne. The results will be used to
form a plasmaspheric Ne database that will be made available to the
scientific community.

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Plasma Physics Seminar, Department of Physics, Dartmouth, 9 November 2004