author = "Moraes, Alison de O. and Vani, Bruno C. and Costa, Emanoel and 
                         Sousasantos, Jonas and Abdu, Mangalathayil Ali and Rodrigues, 
                         Fabiano da Silveira and Gladek, Yuri C. and Oliveira, C{\'e}sar 
                         B. A. de and Monico, Jo{\~a}o F. Galera",
          affiliation = "{Instituto de Aeron{\'a}utica e Espa{\c{c}}o (IAE)} and 
                         Instituto Federal de Educa{\c{c}}{\~a}o, Ci{\^e}ncia e 
                         Tecnologia de S{\~a}o Paulo and {Pontif{\'{\i}}cia Universidade 
                         Cat{\'o}lica do Rio de Janeiro (PUC-Rio)} and {Instituto 
                         Tecnol{\'o}gico de Aeron{\'a}utica (ITA)} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)} and {University of Texas 
                         at Dallas} and EMBRAER and {Instituto Tecnol{\'o}gico de 
                         Aeron{\'a}utica (ITA)} and {Universidade Estadual Paulista 
                title = "Ionospheric scintillation fading coefficients for the GPS L1, L2, 
                         and L5 frequencies",
              journal = "Radio Science",
                 year = "2018",
               volume = "53",
               number = "9",
                pages = "1165--1174",
                month = "Sept.",
             keywords = "ionospheric scintillation, fading coefficients, GNSS 
             abstract = "The terrestrial ionosphere over low-latitude regions presents the 
                         unique phenomena of the equatorial ionization anomaly 
                         (characterized by global maximum in plasma concentration) and 
                         plasma-depleted regions known as equatorial plasma bubbles and 
                         associated smaller-scale plasma irregularities. Transionospheric 
                         radio signals such as those from Global Navigation Satellite 
                         Systems constellations, traveling across this ambient, may suffer 
                         severe scintillation in amplitude and phase due to these plasma 
                         structures. Presently, three civilian signals available for GPS 
                         users, at L1 (1575.42MHz), L2C (1227.60MHz), and L5 (1176.45MHz) 
                         are used to investigate the propagation effects due to these 
                         irregularities. The purpose of the present work is to evaluate 
                         statistically the distribution of severe fade events for each of 
                         these carrier frequencies based on the nonlinear ionospheric 
                         propagation effects as represented by the fading coefficients of - 
                         distribution. The results from the analyses of data sets recorded 
                         by stations at different geomagnetic latitude locations in Brazil 
                         show that regions closer to the equatorial ionization anomaly 
                         crest present higher probability of severe fade events. 
                         Additionally, the L5 signals, dedicated for safety-of-life 
                         applications, revealed more unfavorable results when compared to 
                         the L1 and L2C frequencies. The results further showed that for 
                         0.8S(4)1.0 the probabilities of fades deeper than -10dB were 
                         between 8.0% and 6.5% depending on the station position. 
                         Considering the case of fades deeper than -20dB, the results reach 
                         values near 1%, which is quite concerning. These results show 
                         empirically the fading environment that users of the new civilian 
                         signals may experience in low-latitude region. Additionally, the 
                         fading coefficients may help in the comprehension of the 
                         distribution of amplitude scintillation and its relation with the 
                         frequency used, aiding in the future the development of signal 
                         processing algorithms capable to mitigate errors for navigation 
                  doi = "10.1029/2018RS006653",
                  url = "http://dx.doi.org/10.1029/2018RS006653",
                 issn = "0048-6604",
             language = "en",
           targetfile = "moraes_ionospheric.pdf",
        urlaccessdate = "30 nov. 2020"