GEO卫星姿态偏置对点波束覆盖范围影响

Influence of GEO satellite attitude deviation on spot-beam coverage area

采用多点波束天线技术的GEO卫星在空间运行过程中受地球引力场不均匀、太阳辐射压力变化等因素的影响通常存在滚动姿态、俯仰姿态和偏航姿态的偏差,其点波束的覆盖范围随着偏差角度的变化而变化。滚动偏差造成点波束覆盖范围产生南北方向位移,俯仰偏差造成点波束覆盖范围产生东西方向位移,偏航偏差造成点波束覆盖范围绕星地连线旋转,在南北和东西方向都产生位移。通过理论分析和公式推导,提出卫星滚动偏差、俯仰偏差和偏航偏差对点波束覆盖范围变化影响的计算模型。在实际工程应用中,基于该模型结合点波束偏移量可以逆向推导出卫星的姿态偏差,为卫星姿态控制提供支撑。

The GEO satellites based on multi-point beam antenna technology are usually affected by the factors such as asymmetric earth′s gravitational field and variational solar radiation pressure during the space operation,which may generate the deviations of roll attitude,pitch attitude and yaw attitude,and make the coverage area of the spot-beam change with the angle of deviation.The roll attitude deviation may generate the south-north directional displacement of the spot-beam coverage area.The pitch attitude deviation may generate the east-west directional displacement of the spot-beam coverage area.The yaw attitude deviation makes the spot-beam coverage area rotate around the satellite-to-earth axis,which may generate the omnidirectional displacement.On the basis of theoretical analysis and formula derivation,the calculation model is proposed in this paper,which can reflect the influence of roll attitude deviation,pitch attitude deviation and yaw attitude deviation on the spot-beam coverage area.In the practical engineering applications,the satellite attitude deviation can be derived reversely by the calculation model combined with the spot-beam offset,which provides a support for satellite attitude control.