Building resilience of the Global Positioning System to space weather

In the framework of the project BIS - Bipolar Ionospheric Scintillation and Total Electron Content Monitoring, the ISACCO-DMC0 and ISACCO-DMC1 permanent monitoring stations were installed in 2008.The principal scope of the stations is to measure the ionospheric total electron content (TEC) and to monitor the ionospheric scintillations, using high-sampling-frequency global positioning system (GPS) ionospheric scintillation and TEC monitor (GISTM) receivers. The disturbances thatthe ionosphere can induce on the electromagnetic signals emitted by theGlobal Navigation Satellite System constellations are due to the presenceof electron density anomalies in the ionosphere, which are particularly frequentat high latitudes, where the upper atmosphere is highly sensitive toperturbations coming from outer space. With the development of present and future low-frequency space-borne microwave missions (e.g., Soil Moisture and Ocean Salinity [SMOS], Aquarius, and Soil Moisture ActivePassive missions), there is an increasing need to estimate the effects of the ionosphere on the propagation of electromagnetic waves that affectssatellite measurements. As an example, how the TEC data collected at Concordia station are useful for the calibration of the European Space Agency SMOS data within the framework of an experiment promoted by the European Space Agency (known as DOMEX) will be discussed.The present report shows the ability of the GISTM station to monitor ionospheric scintillation and TEC, which indicates that only the use of continuous GPS measurements can provide accurate information on TECvariability, which is necessary for continuous calibration of satellite data