@InProceedings{RaoLope:1995:FiExFi,
               author = "Rao, K. R. and Lopes, Roberto Vieira da Fonseca",
                title = "Satellite attitude follow-up: a first-hand experience with the 
                         first Brazilian satellite SCD-1",
            booktitle = "Proceedings...",
                 year = "1995",
                pages = "777--783",
         organization = "International Symposium on Space Dynamics.",
             keywords = "ENGENHARIA E TECNOLOGIA ESPACIAL, Brazilian satellite, SCDI, 
                         Complete Brazilian Space Mission (MECB), spin-axis, attitude 
                         monitoring.",
             abstract = "The first Brazilian satellite SCDI, designed and manufactured by 
                         the Instituto Nacional de Pesquisas Espaciais - INPE under the 
                         Complete Brazilian Space Mission (MECB) project, was launched on 
                         February 09, 1993 at 14:42:20 UTC by a Pegasus rocket of Orbital 
                         Sciences Corporation of USA. It is a spin-stabilized satellite and 
                         its thermal constraints prohibit the orientation of the spin-axis 
                         with respect to Sun's direction to rise above 90 degrees. Due to 
                         this condition, some type of spin-axis attitude monitoring was 
                         necessary during the useful lifetime of the satellite. Although 
                         various types of algorithms were developed for this purpose, 
                         unexpectedly, a software, which was developed during the 
                         satellite's mission analysis phase mainly in order to furnish the 
                         miss ion analysts with a fast, clear and integrated visualization 
                         of the preliminary attitude determination results and related 
                         aspects, was found useful for this purpose. For each orbit during 
                         a specified period, this software prepares and draws on a computer 
                         terminal, or optionally on a plotter, in inertial celestial sphere 
                         containing: the Sun's position; the Earth's shadow; the 
                         geomagnetic field vector trajectory; the satellite trajectory 
                         during its pass over a given ground station; and the attitude of 
                         the satellite spin-axis enveloped by its predicted uncertainty 
                         ellipse. A rational analysis of this map helps a mission analyst 
                         to select an optimum sub-set of satellite passes in order to 
                         achieve the best possible precision in the attitude determination 
                         process. However, besides fulfilling this main objective, after 
                         the SCD1 launch. the attitude determination software was found to 
                         be useful for various other purposes such as: the study of 
                         magnetometer bias fluctuations, observed from one pass of the 
                         satellite to other; an easy-monitoring of the spin-axis attitude 
                         etc. This software also helped the mission analysts to take some 
                         important decisions in improving the main attitude determination 
                         software. This paper narrates everything about the attitude 
                         follow-up software, starting from the initial idea based on which 
                         the software was developed till the developments along time and 
                         its final function. Being a debut of the attitude team of the 
                         flight mechanics group of INPE, the experience with SCDI related 
                         to attitude determination process gave challenging problems as 
                         well as pleasant surprises, some of which are from the attitude 
                         follow-up software. The main idea of this work is to share our 
                         first-hand experience with the first Brazilian satellite SCD I in 
                         the process of its attitude follow-up.",
  conference-location = "Toulouse, FR",
      conference-year = "19-23 June 1995",
                label = "10928",
           targetfile = "rama_satellite.pdf",
        urlaccessdate = "04 maio 2024"
}