岩田 隆浩

The solar radiation pressure model for the sub-satellites RSAT and VSAT in the SELENE project is improved to correct the mean acceleration due to an evolving tip-off of the spin during the life time of satellites. The shape of the satellites is assumed to be a regular octagonal pillar. Solar radiation pressure force components acting on each surface element of the satellite are calculated independently and summed vectorially during a total period of Euler's free nutation of the satellite to obtain the mean acceleration of the satellite center of mass. The Doppler tracking data reduction process for the RSAT is simulated after incorporating the modified model into the orbit analysis software. Comparing with two other types of solar radiation pressure models, the standard cannonball model and a non tip-off model, it is found that when the tip-off becomes larger than 5°/s, the orbit determination result of using the modified model is better than the results of using other ones.