二次成像型库德式激光通信终端粗跟踪技术

库德式激光通信终端粗跟踪探测器大视场接收信标光时,需通过望远单元、多块库德反射镜、分光片和粗跟踪透镜组,信标光传输路径长,使得后续子光路粗跟踪支路口径明显增加;捕获时望远单元和库德反射镜与粗跟踪探测器存在相对运动,信标光传递环节多,跟踪模型复杂。针对这两个问题,首先,对比了3种传统库德光路,选择二次成像型库德光路并对其进行设计,通过设计使后续子光路光学口径减小,利于后续子光路轻小型化设计;随后,对二次成像型库德式激光通信终端的跟踪模型进行推导,通过反射镜矩阵和坐标变换建立跟踪模型,并用Matlab-Simulink对跟踪模型进行仿真;最后,通过地面试验,对终端的跟踪性能进行测试,实测方位跟踪最大脱靶量为84.65μrad(3σ)、俯仰最大脱靶量为56.33μrad(3σ),满足通信要求的150μrad(3σ),二次成像型库德结构和跟踪模型可满足星间激光通信粗跟踪捕获和跟踪要求。

Coarse tracking technology of secondary imaging Coude-type laser communication terminal

When the Coude-type laser communication terminal coarse tracking detector receives the beacon light in a large field of view, it needs to pass through the telephoto unit, a plurality of Coude mirrors, a beam splitter, and a thick tracking lens group, so the long beacon light transmission path results in a significant increase in the optical aperture of following sub-optical path coarse tracking branch. At the time of capture, telescopic units and Coude mirrors have relative motion with the coarse tracking detectors, there are many beacon light transmission links and the tracking model is complex. To solve these two problems, first, three kinds of traditional Coude light paths are compared, the secondary imaging Coude optical path is selected and designed to reduce the optical aperture of the subsequent sub-optical path, which is conducive to the subsequent light and miniaturization design of the sub-beam path. Subsequently, the tracking model of the secondary imaging Coude-type laser communication terminal is deduced, the tracking model is established by the mirror matrix and coordinate transformation, and the tracking model is simulated by Matlab-Simulink; finally, through the ground test, the tracking performance of the terminal is evaluated. The maximum target miss distance of azimuth tracking is 84.65 μrad(3σ), and the maximum target miss distance of pitch tracking is 56.33 μrad(3σ), which satisfies the communication requirements of 150 μrad(3σ). The secondary imaging Coude-type structure and tracking model meet the requirements of coarse tracking acquisition and tracking of inter-satellite laser communication.