卫星光通信终端CCD成像光斑弥散圆尺寸选择

利用CCD对自由空间传输的激光进行成像,可得到入射光束的角度信息以实现对发射光束的控制。卫星光通信中,提高对入射光束角度偏差实时测量的精度,可以有效地提高终端的光束跟踪性能,进而有效地保持激光链路的稳定。通过分析角度偏差检测原理,建立了卫星光通信中跟瞄装置测角性能分析模型。分析了测角精度与CCD成像光斑弥散圆尺寸之间的关系,并通过模拟实验进行了验证。结果表明,在卫星光通信系统设计中,综合考虑测角精度要求、终端功耗限制等因素,选择CCD成像光斑相对尺寸在2到3之间为最佳。

Size Selection of Dispersive Spot Imaging on CCD in a Satellite Optical Communication Terminal

The propagating laser in free space was imaged by charge coupled device (CCD), so the incidence beam angles information can be obtained for the transmitting laser beam control. In satellite optical communications, improving the real-time measure precision for the angle errors of the incoming beam, higher tracking performance of a terminal can be reached and the laser link can be maintained steadily. The principium of the beam angle errors measurement was analyzed, and a model was founded for the angle errors measurement capability evaluation of the tracking assembly in satellite optical communications. The relationship of angle errors measurement precision with the size of dispersive spot imaging on CCD was analyzed using the model, and then some experiments were implemented to validate the results. It showed that considering the requirement for angle measurement precision and condition of the terminal power limitation, the relative size of the spot imaging on CCD should be between 2 and 3 in the design of a satellite optical communication system.