The ionosphere is one of the biggest sources of systematic errors in the positioning by GNSS (Global Navigation Satellite System), due to the observables be affected by various ionospheric conditions arising from changes in space weather. Thus, investigations related to the ionized layer of the atmosphere are of utmost importance. In recent years the space weather has aroused great national and international interest. The advent of various missions to study the Sun from remote sensing, such as the SOHO (Solar and Heliospheric Observatory) and STEREO (Solar Terrestrial Relations Observatory), aroused the interest in understanding the influence of the Sun and its impact on geotechnologies. Nationally, INPE (National Institute for National Research), one of the major organs in the study of space phenomena, is responsible for the EMBRACE program (Study and Monitoring Brazilian Space Weather), whose mission is the monitoring, modeling and dissemination of information of space weather. Develop new algorithms and improve existing ones, in order to minimize the effects of the ionosphere, especially in high-accuracy GNSS techniques, is one of the main strands of Space Geodesy, due to the increased of solar activities in the triennium 2013-2014-2015. Thus, the project aims at the use of GNSS data from stations of GNSS-SP (Active GNSS Network of the State of São Paulo), CALIBRA (Countering high Accuracy GNSS applications Limitations due to Ionospheric disturbances in BRAzil) and RBMC (Brazilian Network of Continuous Monitoring) networks in estimating of ionospheric irregularity indexes and ionospheric scintillation indexes in the modalities post-processed and real time, thus transforming monitoring stations of GNSS signals in ionospheric monitoring stations. This densification of stations allows a larger set of data and an increase in the spatial resolution, since the number of instruments dedicated to monitoring the ionosphere in Brazil is reduced, thereby enabling a better understanding of ionospheric phenomena. For this research was developed a program called Ion_Index. Experiments were performed in order to evaluate the estimates of irregularity and scintillation indexes for a period of high and a low variability of the electron density. The results were compared with data from other sources and proved compatible. Experiments using the indexes of irregularities and the ionospheric scintillation indexes were also performed in order to monitor the effects of seasonal variation and moments of rise and peak of the solar cycle 24 on Brazilian territory. The proposal of a scintillation index based on measures of SNR (Signal to Noise Ratio) was investigated and is presented.
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