ASTRA regularly conducts scientific investigations of the state of the ionospheric (and plasmaspheric) plasma and are working to understand how the ionosphere responds to changes in the inputs and coupling mechanisms which therefore will improve the understanding of the underlying physics. The electron density is one of the most copiously observed ionospheric state variables and is one of the primary responses to the physical drivers and interactions that govern the solar, magnetosphere, ionosphere coupling and dynamics.
Understanding the small (on the order of meters (or less) to a few kilometers) and large scale (few hundred kilometers horizontally and ~ 10 km vertically) 3-D time evolving distributions of electron density throughout the ionosphere and plasmasphere is important to RF applications. The electron density can produce a time delay, advance the phase, and refract (bend) the RF signals, thus disrupting GPS and satellite communications.
Electron Density is measured by several space sensors as well as over 1500 GPS receivers world wide.