Ionosphere Propagation Environnement Mitigation – SEPI

The understanding of the space weather and the disturbances of the iono-magnetosphere is a challenging matter for many institutions. The spatial industries, agencies and research institutes must maintain the highest standards for the design of their satellites, instruments and data processing algorithms, which become more and more vulnerable to disturbances. The Defence must ensure the highest reliability of its tactical communication means. The air companies, which use HF communications, are also affected by the iono-magnetospheric disturbances.
That's why the space weather research is very active with ambitious programs such as "Living With a Star" funded by the NASA, "Space Situational Awareness" from ESA and the FP7 program of the EU. That’s how NOVELTIS have used its expertise in data assimilation and its experience about the ionospheric dynamics in two european projects: SOTERIA (Solar Terrestrial Investigation and Archives) and eHEROES (Environnement for Human Exploration and Robotic Experimentation in Space).
The SEPI (Ionospheric Propagation Environment Surveillance) project has a double goal: studying the consequences of the iono-magnetospheric disturbances in space and in the atmosphere. In order to establish a preliminary basis for space surveillance system, SEPI will design surveillance system of the propagation conditions of the electromagnetic waves. This tool will address many military, social and economical needs: the Defence (HF communications), air companies (flight and staff security) and earth observing missions (design and usage of P-band RADARs).
Two ambitious approaches were chosen: the detection of ionospheric disturbances and the re-updating of the HF propagation channel.
The detection of the ionospheric disturbances will address scientific and non-scientific needs for the applications described above. Key parameters to monitor are the sudden D-region ionisation, the geomagnetic field compressions, the particles precipitations and the ionospheric scintillations. Many observation means are reliable: geostationary or low-orbit satellites, HF radar, ionosonde, ISM, magnetometer, GPS analysis, etc.). Two measurements are especially innovative and scientifically and technologically challenging. First, the data processing of the GPS network is way to analyze the ionospheric dynamic on the whole globe: we'll focus on the study of the auroral oval changes (intensity, extension). Finally, using local geomagnetic field measurements could help characterizing locally the impact of the ionospheric propagation conditions disturbances.
The re-updating of the HF propagation channel addresses specific needs of the Defence. The main goal is to use Signals-of-opportunity to characterize the channel when there is a sudden ionospheric event. In this context, we'll be allowed to use a unique database of HF Spectra of opportunity measured by the DGA in order to identify the stable sources. Recognizing the different causes of the signals variability is a technological challenge, which we will study by using colocalized signals to restrain the variabilities with redundancies. The other technological challenge is the precise characterization of the absorption during the sudden ionospheric events. This characterization will be done with the selected HF sources. A calibration using reference models (computed from data or pre-computed) when there is no ionospheric event is also envisaged.
So this project will provide a re-updating of the ionospheric propagation channel and also an innovative detection method for the disturbances of the ionospheric propagation conditions.