3-dimensional ionospheric electron density reconstruction based on GPS measurements

Abstract

When GPS navigation system radio waves pass trough the ionosphere and plasmasphere they are subject to delays in phase, travel time and polarisation, owing to the presence of free electrons. The integrated values of Total Electron Content can be used for 3-dimensional reconstruction of ionospheric electron density patterns. Here a tomographic approach is presented. Since the input data are sparsely distributed and patchy we chose an algebraic iterative algorithm. A plasma convection event has been taken as a tomographic case study. The addition of limb sounding GPS from Low Earth Orbiter satellites improves reconstructions of the vertical shape of the ionosphere by its horizontally viewing rays. A reconstruction including an occultation event is presented and the results are validated using an ionosonde profile.