Date of Award


Document Type


Degree Name

Master of Science


Department of Engineering Physics

First Advisor

Ariel O. Acebal, PhD.


The Floating Potential Measurement Unit (FPMU) aboard the International Space Station (ISS) monitors the ISS charging environment and provides a unique electron density and electron temperature in-situ data source for the purpose of ionospheric model validation. An ionospheric model that accurately predicts the ISS plasma environment is desirable for ISS mission planning and situational awareness when FPMU data is unavailable. Electron densities and temperatures from four ionospheric models (International Reference Ionosphere [IRI], Coupled Thermosphere Ionosphere Plasmasphere Electrodynamics model [CTIPe], Ionospheric Forecast Model [IFM], and Global Assimilation of Ionospheric Measurements model [GAIM]) were compared to in-situ FPMU values across a range of geomagnetic and solar conditions. The climatological and assimilative models (IRI and GAIM) performed the best overall across all conditions, while the pure physics based models (IFM and CTIPe) struggled the most to accurately predict the ISS plasma environment. IRI-2012 and GAIM represent the best candidates for use by NASA as an ISS mission planning tool.

AFIT Designator


DTIC Accession Number


Included in

Physics Commons