author = "Pardal, P. C. P. M. and Moraes, R. V. De and Kuga, H{\'e}lio 
          affiliation = "{Universidade de S{\~a}o Paulo (USP)} and {Universidade Federal 
                         de S{\~a}o Paulo (UNIFESP)} and {Instituto Nacional de Pesquisas 
                         Espaciais (INPE)}",
                title = "Effects of geopotential and atmospheric drag effects on frozen 
                         orbits using nonsingular variables",
              journal = "Mathematical Problems in Engineering",
                 year = "2014",
               volume = "2014",
             keywords = "Drag, Satellites, Analytical expressions, Argument of perigees, 
                         Atmospheric drag, China-brazil earth resources satellites, 
                         Classical equation, Non-singular variables, Orbital evolutions, 
                         System of nonlinear differential equations, Orbits.",
             abstract = "The concept of frozen orbit has been applied in space missions 
                         mainly for orbital tracking and control purposes. This type of 
                         orbit is important for orbit design because it is characterized by 
                         keeping the argument of perigee and eccentricity constant on 
                         average, so that, for a given latitude, the satellite always 
                         passes at the same altitude, benefiting the users through this 
                         regularity. Here, the system of nonlinear differential equations 
                         describing the motion is studied, and the effects of geopotential 
                         and atmospheric drag perturbations on frozen orbits are taken into 
                         account. Explicit analytical expressions for secular and long 
                         period perturbations terms are obtained for the eccentricity and 
                         the argument of perigee. The classical equations of Brouwer and 
                         Brouwer and Hori theories are used. Nonsingular variables approach 
                         is used, which allows obtaining more precise previsions for CBERS 
                         (China Brazil Earth Resources Satellite) satellites family and 
                         similar satellites (SPOT, Landsat, ERS, and IRS) orbital 
                         evolution.  2014 Paula Cristiane Pinto Mesquita Pardal et al.",
                  doi = "10.1155/2014/678015",
                  url = "http://dx.doi.org/10.1155/2014/678015",
                 issn = "1024-123X",
                label = "scopus 2014-11 PardalMoraKuga:2014:EfGeAt",
             language = "en",
        urlaccessdate = "30 nov. 2020"