Ionospheric Signal Propagation Simulator for Earth Observation Missions

Abstract

Following the discovery of the ionosphere by Marconi in 1901, different disciplines have been influenced from the ionospheric effects on radio-waves, such as communications or Earth Observation missions. The ionosphere acts as an electrical layer that is continuously changing due mainly to solar activity. Therefore, it is not a trivial work to predict how radio signals would be affected. This study presents the implementation of a Matlab ray-tracer to predict radio-wave propagation through the ionosphere. This program is inspired on a Fortran code developed in the 70's, but it is extended to include the state-of-the-art models, such as the IRI (International Reference Ionosphere), the IGRF (International Geomagnetic Reference Field), and the NRLMSISE-00 (Naval Research Lab, atmospheric model). A statistical model of bubbles and depletions is also included for increased accuracy. The simulator provides several graphs and a text document, both summarizing the ray trajectories and main propagations effects. This tool is being developed as part of an ESA project devoted to the study of ionospheric effects in low frequency radars, namely radar sounders and Synthetic Aperture Radars, and GNSS systems.