Sensitivity of Ionospheric Specifications to In Situ Plasma Density Observations Obtained From Electrostatic Analyzers Onboard of a Constellation of Small Satellites

Sensitivity of Ionospheric Specifications to In Situ Plasma Density Observations Obtained From Electrostatic Analyzers Onboard of a Constellation of Small Satellites

Our ability to specify and forecast ionospheric dynamics and weather at low- and mid-latitudes is strongly limited by our current understanding of the coupling processes in the ionosphere-thermosphere system and the coupling between the high and low latitude regions. Furthermore only a limited number of observations are available for a specification of ionospheric dynamics and weather at these latitudes. As shown by meteorologists and oceanographers, the best specification and weather models are physics-based data assimilation models that combine the observational data with our understanding of the physics of the environment. Through simulation experiments these models can also be used to study the sensitivity of the specification accuracy on different arrangements of observation platforms and observation geometries and can provide important information for the planning of future missions. For example, these studies can provide information about the number of spacecraft needed to improve the specification or evaluate the impact of different observation geometries on the accuracy of the specification. Here we have used the Global Assimilation of Ionospheric Measurements Full-Physics model (GAIM-FP) to study the sensitivity of ionospheric specifications on in situ plasma density observations obtained from electrostatic analyzers (ESA) onboard of a constellation of small satellites. The model is based on an Ensemble Kalman filter technique and a physics-based model of the ionosphere/plasmasphere (IPM), which covers the altitude range from 90 to 20,000 km. The data assimilation model can, in addition to the ESA observations, assimilate bottom-side Ne profiles from ionosondes, slant TEC from ground-based GPS stations, in situ Ne from DMSP satellites, occultation data from several satellites, and line-of-sight UV emissions measured by satellites. Simulation studies have been performed using various ESA constellation arrangements and their impact on the ionospheric specification has been evaluated. The results from this study will be presented with an emphasis on the number of satellites and their orbital geometries needed to improve ionospheric specifications and forecasts.