基于单星光学探测数据进行初轨确定是空间态势感知的重要研究方向。该领域的研究主要集中在如何仅用测角信息进行初轨确定，部分论文探讨了在特定条件下初轨确定问题的可观测性，但还缺乏对可观测性的一般性理论证明。在理想二体运动模型假设下，文章从理论上证明了除共面轨道和双子轨道这2种场景外，基于单星测角数据可以唯一确定目标轨道，即一般情况下初轨确定是可观测的。此外，还通过数值仿真对结论进行了验证。该结论揭示了天基光学观测初轨确定问题的部分基础特性，有助于进一步优化相关初轨确定算法。

Initial orbit determination based on bearings-only measurements is an important research direction in space situational awareness. The research in this field mainly focuses on how to determine the initial orbit using bearings-only measurement. Some studies have explored the observability of initial orbit determination under specific conditions， but there is still a lack of general theoretical proof of observability. Under the assumption of an ideal two-body motion model， this article theoretically proves that except for the two scenarios of coplanar orbit and twin orbits， the target orbit can be uniquely determined based on single satellite bearings-only measurement， that is， the initial orbit determination is generally observable. The conclusion is also verified by numerical simulation. This conclusion reveals some basic characteristics of the problem of initial orbit determination for space-based optical observations， and is helpful for further optimizing the algorithms for initial orbit determination.