author = "Hernandez, Felipe Pellegrini and Moraes, Alison de Oliveira and 
                         Paula, Eurico Rodrigues de and Perrella, Waldecir",
          affiliation = "EMBRAER and {Instituto de Aeron{\'a}utica e Espa{\c{c}}o (IAE)} 
                         and {Instituto Nacional de Pesquisas Espaciais (INPE)} and 
                         {Instituto Tecnol{\'o}gico de Aeron{\'a}utica (ITA)}",
                title = "Ionospheric scintillation incidence probability for different 
                         levels of solar and magnetic activities over braziliaan 
                 year = "2017",
         organization = "International Congress of the Brazilian Geophysical Sociey, 15.",
             abstract = "The navigation and Positioning using satellite became essential in 
                         many areas, for instance in the terrestrial navigation, precise 
                         agriculture, aircraft landing, no manned aircraft control, 
                         petroleum prospection, between many other applications. Many 
                         factors can affect the performance of these navigation systems, 
                         like inclement weather, multipath, the troposphere, the ionosphere 
                         and even jammings. These interferences, depending of their 
                         severity intensity can degrade the positioning systems and even to 
                         interrupt the navigation, what can eventually affect one 
                         substantial number of users. Between the sources of positioning 
                         errors using GPS, the ionosphere in the Brazilian territory is 
                         probably the most important factor that has influence over the 
                         positioning. The ionosphere causes delays and advances in the 
                         carrier and code signal, that result in pseudorange errors. 
                         Besides those effects, the GPS signal, when crossing the 
                         ionospheric bubbles with depleted densitites, suffers variations 
                         in the amplitude and phase, what is named ionospheric 
                         scintillation. The scintillation affects the receiver performance 
                         through signal distortions that produce positioning errors or in 
                         extreme events can interrupt the system operation. In this work it 
                         is presented one ionospheric scintillation analysis of the GPS 
                         signal based on the scintillation occurrence intensity during the 
                         spring and summer solstice for the 2013 to 2016 years. The 
                         analyzed data were obtained from two stations located at 
                         Presidente Prudente and S{\~a}o Jos{\'e} dos Campos, both in the 
                         S{\~a}o Paulo state. These stations are located in a region 
                         suitable for this kind of study since they are located in low 
                         latitude and under the crest of the equatorial ionization anomaly. 
                         The aim of this work is to propose a set of equations to represent 
                         the scintillation occurrence probability in these stations during 
                         two seasons of the year. The input parameters for the proposed 
                         approximations are the Kp index representing the magnetic 
                         intensity and the F10.7 cm representing the solar flux level. The 
                         proposed equations representing the scintillation estimative are 
                         validated not only with Presidente Prudente and S{\~a}o Jos{\'e} 
                         dos Campos data, but also using data from the station of 
                         Inconfidentes in the Minas Gerais state. So this model will allow 
                         users to estimate the expected scintillation night-by-night based 
                         on the Kp and F10.7 values and they will be able to predict its 
                         incidence and consequently to reduce its impact mainly during more 
                         severe scintillation events.",
  conference-location = "Rio de Janeiro, RJ",
      conference-year = "31 jul. - 03 ago.",
           targetfile = "hernandez_ionospheric.pdf",
        urlaccessdate = "30 nov. 2020"