@InProceedings{FrancoEcheFraeBolz:2018:StStCo,
               author = "Franco, Adriane Marques de Souza and Echer, Ezequiel and Fraenz, 
                         Markus and Bolzan, Mauricio Jose Alves",
          affiliation = "{} and {Instituto Nacional de Pesquisas Espaciais (INPE)} and {Max 
                         Planck Institute for Solar System Research} and {Universidade 
                         Federal de Goi{\'a}s (UFG)}",
                title = "A statistical study of correlation length around Venus",
                 year = "2018",
         organization = "Latin American Conference on Space Geophysics, 11. (COLAGE)",
             abstract = "A statistical study of the correlation scale on structures around 
                         Venus was developed using magnetic field and electron density data 
                         obtained from the Magnetometer and the Analyzer of Space Plasmas 
                         and Energetic Atoms (ASPERA-4) instruments (respectively), on 
                         board of the mission Venus Express (VEX). The correlation scales 
                         have been calculated by the correlation length, which is a 
                         characteristic length over which fluctuations in a variable are 
                         correlated. We limited the study to the frequency range 8 to 50 
                         mHz because previous studies have shown that ULF (Ultra Low 
                         Frequency) waves produced in the foreshock have highest power in 
                         this range. Frequencies below 8mHz were filtered out using the 
                         Fourier transform. In this study the correlation length was 
                         calculated by an exponential fit employed to the autocorrelation 
                         curve. The auto-correlation function was calculated lagged by a 
                         time between 0 and 60 seconds and sliding a window of 120s width 
                         across the data. We also converted the obtained correlation length 
                         from temporal to spatial scale by multiplying by the solar wind 
                         velocity. Here, the ASPERA-4/IMA (Ions Mass Analyzer) velocity was 
                         used. In order to find the size of the structure in different 
                         regions of the Venus magnetosphere, statistical maps showing the 
                         median correlation length in spatial bins around Venus have been 
                         produced covering the all data from the VEX mission (May 2006 to 
                         September 2014).",
  conference-location = "Buenos Aires, Argentina",
      conference-year = "16-20 abr.",
             language = "en",
        urlaccessdate = "28 abr. 2024"
}