author = "Carrara, Valdemir",
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)}",
                title = "An Open Source Satellite Attitude and Orbit Simulator Toolbox for 
            booktitle = "Proceedings...",
                 year = "2015",
               editor = "Steffen Junior, V. and Rade, D. A. and Bessa, W. M.",
         organization = "International Symposium on Dynamic Problems of Mechanics, 17.",
            publisher = "ABCM",
             keywords = "attitude control, orbit propagation, attitude simulation.",
             abstract = "In recent years computer simulation has evolved to accomplish to 
                         newer and better technologies, taking the benefit of fast 
                         computers, multi core processors and new visualization tools, not 
                         to mention new paradigm in manmachine interfaces. Although 
                         interpreted languages, like Matlab, are still slow when compared 
                         with compiled ones (Fortran and C, for instance), the number of 
                         real-time applications with Matlab has increased over time, due 
                         mainly its intrinsic ability to handle matrices and the large 
                         amount of libraries, toolboxes and ready-to-use applications for 
                         both Matlab and Simulink. These facts suggest that Matlab has to 
                         be considered as a promising host for any simulation module, which 
                         reinforces the necessity of reliable simulation packages written 
                         in this language. Following these guidelines, the PROPAT package 
                         of Matlab functions has been developed, to simulate Earths 
                         satellites orbit and attitude. The package includes an analytical 
                         orbit propagator, allied to a numerical attitude propagator. 
                         Nutation dampers and reaction wheels can be easily added to the 
                         rigid body dynamics. Also available are functions to compute the 
                         position of the Sun relative to Earth, the geomagnetic field in a 
                         given satellite position, the Greenwich sidereal time and a 
                         function to check if the satellite is in the Earth shadow. Several 
                         functions to compute coordinate transformation and ephemeris 
                         calculation were included into the package, both for orbital 
                         elements (state vector, Keplerian elements or geocentric 
                         coordinates) and attitude (Euler angles, quaternion, cosine 
                         directors matrix, and Eulers axis and angle), among others. The 
                         PROPAT package has being employed at INPE (National Institute for 
                         Space Research, in Brazil) for attitude control simulation and 
                         orbit and attitude analysis. This paper presents the description 
                         of the PROPAT conception, as well as some simulations performed 
                         with this package, including the design of the attitude control 
                         system of the CubeSat NBR-2 and the CONASAT constellation 
  conference-location = "Natal, RN",
      conference-year = "22-27 Feb.",
             language = "en",
           targetfile = "carrara_open.PDF",
        urlaccessdate = "24 nov. 2020"