追踪及凝视状态下地气光对空间目标成像影响

为了分析不同探测方式下地气光辐射对空间目标成像特性的影响，利用卫星仿真工具包（satellite tool kit，STK）设计了一个以地球同步轨道（geosynchronous orbit，GEO）卫星与中轨道（medium orbit，MEO）卫星上搭载的可见光成像器为探测平台，以高椭圆轨道（highly elliptical orbit，HEO）卫星为观测目标的空间目标运动及探测场景，采用微元法建立空间目标与地气光辐射模型，进而推导出目标信噪比（signal to noise ratio，SNR）。在探测平台上布置追踪探测器与凝视探测器，以进一步分析不同探测模式空间目标与地气光辐射信号及目标SNR的变化规律。仿真结果表明，中轨探测器得到的目标SNR强于高轨探测器，同一探测平台上追踪探测器得到的目标SNR强于凝视探测器，二者在空间目标进出探测器视场时相差最大，在空间目标靠近探测器视场中心时相差最小。

Influence of earth atmosphere radiation on the imaging of space object under tracking and gazing state

In order to analyze the influence of earth atmosphere radiation on imaging characteristics of space object for different detection methods, a moving and detecting scene of space object was designed with STK, where the visible light imagers mounted on the GEO and MEO satellites were set as detecting platform, the HEO satellite was set as object. Models of space object and earth atmosphere radiation were built with infinitesimal method, and then the SNR of space object was derived. Furthermore, both tracking and gazing detectors were disposed on each detecting platform to analyze the change rule of SNR with different detecting models. The simulation results indicate that the target SNR obtained by the middle orbit detector is stronger than the high orbit detector; the target SNR of tracking detector is stronger than that of gazing detector on the same detecting platform; the difference of SNR is maximal as the space object entering or leaving the detecting field of view, yet it is minimal as the object is close to the center of detector's field of view.