基于恒星的电离层成像仪在轨几何定标

三轴稳定的地球静止轨道卫星在轨运行期间温度会有周期性变化.其上装载的远紫外电离层成像仪与卫星之间的热应力变化造成机械传递，导致仪器指向与装星时的初始位置发生偏差.恒星在惯性坐标系中的位置保持不变，可以将其作为电离层成像仪在轨几何定标的定标源.本文建立了基于恒星的电离层成像仪在轨几何定标模型，通过拍摄所筛选恒星图像，得出仪器在轨指向相对于初始值的偏离程度，从而提高电离层成像仪的成像几何精度.通过模拟试验，验证了运用此技术进行在轨几何定标的可行性.研究结果可为电离层成像仪常态化自动在轨几何定标奠定基础. 

On-orbit Geometric Calibration of Ionospheric Imager Based on Stellar

The surface temperature of the three-axis stabilized Geostationary Orbit(GEO)satellite will change periodically during orbital operation.The thermal stress changes of the far-ultraviolet ionospheric imager and the satellite cause mechanical transmission,which causes the instrument pointing to deviate from the initial position as it is installed on the satellite.Stellar position in the inertial coordinate system remains constant,which can be used as the calibration source for the on-orbit geometric calibration of the ionospheric imager.An on-orbit geometric calibration model based on stellar is established.By taking images of the selected stellar,the deviation of the instrument on-orbit pointing from the initial value is obtained,and the imaging geometric accuracy of the ionospheric imager is improved.Finally,a simulation experiment is carried out to verify the feasibility of using this technique to perform on-orbit geometric calibration.