Several models were developed using GNSS (Global Navigation Satellite System) observations to represent the ionosphere in Vertical Total Electron Content (VTEC) maps. Nowadays, valuable information of the ionosphere is constantly released by IGS (International GNSS Service) in global VTEC maps. However, VTEC modeling errors occurs due to the consideration of the ionosphere as a thin shell with constant height. By contrast, ionosphere is a layer with more than 1000 km thickness. Ionospheric profiles may be retrieved using tomographic reconstruction techniques, which are based on GNSS observations to map the ionosphere in three dimensions. Therefore, the tomographic products may be used for several applications of Aeronomy, Geodesy, Space Weather and Telecommunications. However, performing tomographic reconstructions using only ground stations shows deficiencies in vertical representations of the ionosphere. To overcome this geometric deficiency, data assimilation can be performed including radio-occultation data and ionospheric profiles in the tomographic reconstruction. Many researchers have already proposed tomographic reconstruction methods with data assimilation; however it still presents a continuous challenge for scientific community, mainly in global scale, ionospheric low-latitude regions and for GNSS positioning applications. Therefore, the research project aims to study tomographic reconstruction methods of the ionosphere using data assimilation, which is closely related with some projects going on at Universitat Politècnica de Cataluny (UPC). In this context, the main goals of this internship with UPC are: to obtain experience with global ionospheric models developed by UPC; to develop appropriate techniques for using tomographic algorithms for GNSS positioning applications; and to accomplish analyses of the ionospheric dynamics over Brazil by the tomographic products.
News published in Agência FAPESP Newsletter about the scholarship: