SIRIO: One year of station keeping

The strategy followed in maintaining the station point and the results achieved are described. The method used for orbit determination is presented. Azimuth and elevation data from SHF antennas were used as input for the determination. An estimation of the uncertainty of the orbit was given and a comparison was made between determinations performed using the method here described and determinations performed using VHF ranging data. Also, the difference in using data from a single SHF station or two stations was shown. In the area of attitude determination, a study was carried out for predicting the spacecraft spin axis precession. The model used was explained and then the agreement between predicted and measured attitude outlined.