author = "Garcia, Roberta Veloso and Kuga, H{\'e}lio Koiti and Silva, 
                         William Reis and Zanardi, Maria Cecilia",
          affiliation = "{Universidade de S{\~a}o Paulo (USP)} and {Instituto Nacional de 
                         Pesquisas Espaciais (INPE)}",
                title = "Unscented Kalman filter and smoothing applied to attitude 
                         estimation of artificial satellites",
              journal = "Computational and Applied Mathematics",
                 year = "2018",
               volume = "2018",
             keywords = "Rauch–Tung–Striebel smoother · Unscented Kalman filter · Attitude 
                         estimation · Euler angles.",
             abstract = "This article uses the state smoothing methodology applied to 
                         nonlinear systems to refine the attitude of artificial satellites. 
                         In this paper, simulated data of telemetry and ephemeris of a 
                         satellite with the specifications of China Brazil Earth Resources 
                         Satellite are considered and the dynamic system is described by 
                         the set of kinematic equations in terms of the Euler angles and 
                         the bias vector of gyroscope. The estimator used to determine the 
                         forward estimates in time is the Unscented Kalman filter, while 
                         the RauchTungStriebel fixed interval estimator makes the estimate 
                         backward time. The results show that, although the time of the 
                         estimation process is slightly increased, the smoother presents 
                         estimated attitude and bias closer to the real values than the 
                         estimated values when using only the Unscented Kalman filter. 
                         Therefore, the smoother can be considered as a technique that 
                         provides refined measurements of the attitude and bias of the 
                         gyroscope that may serve to calibrate the Kalman filter for next 
                  doi = "10.1007/s40314-018-0576-8",
                  url = "http://dx.doi.org/10.1007/s40314-018-0576-8",
                 issn = "2238-3603",
             language = "en",
           targetfile = "garcia_unscented.pdf",
        urlaccessdate = "25 jul. 2021"