无信标捕跟瞄技术以通信光为信标光, 无需额外的信标光激光器, 在重量和功耗受限的卫星光通信应用中更具优势。针对低轨小卫星平台星间光通信, 对直接探测方式下的捕跟瞄链路进行功率预算分析,研究光通信终端的无信标捕跟瞄技术, 设计捕跟瞄流程, 并深入分析视轴抖动对捕获时间和捕获概率的影响, 提出剩余不确定区域计算方法。结果表明: 所设计的无信标捕跟瞄方法所需最大激光发射功率为0.135 W, 捕获时间为30 s, 捕获概率为95%, 能够满足低轨星间光通信链路要求。

As beaconless acquisition tracking and pointing (ATP) uses the same laser beam with communication, and needs no more extra laser equipment, it has advantages in inter-satellite optical communication application which limits weight and power consumption of laser communication terminals. For scenario of low earth orbit inter-satellite optical communication, beaconless ATP of small optical terminals based on intensity modulation and direct detection was studied. The link budget was calculated, and the ATP procedure was designed. The effect of boresight vibration on acquisition time and acquisition probability was analyzed, and the method of residual uncertainty cone calculation was presented. It shows that the maximum laser transmitting power required is 0.135 W, and beaconless acquisition time is 30 s with acquisition probability of 95%, which can meet requirements of low earth orbit inter-satellite optical communication links.