Zaman Imam Uz, Velazco Jose E, Boyraz Ozdal
Department of Electrical Engineering and Computer Science, The University of California, Irvine, CA 92697, USA.
Jet Propulsion Laboratory, NASA, 4800 Oak Grove Drive, Pasadena, CA 91109.
IEEE Trans Aerosp Electron Syst. 2020 Dec;56(6):4556-4566. doi: 10.1109/taes.2020.2995320. Epub 2020 May 19.
CubeSat swarm in LEO orbit is an attractive alternative to present-day expensive and bulky satellite-based remote sensing systems. This paper presents the design and optimization rules to achieve omnidirectional, high speed, long-range (more than 100 km) data communication among CubeSats. The unprecedented size, weight, power, and cost constraints imposed by the CubeSat platform and the availability of the commercial-off-the-shelf components are considered in the analyses. Analytical studies related to the scanning mirror-based beam steering system as well as scanning mirror's smallest step angle requirement are presented. In addition, we demonstrate the relations and dependencies among scanning mirror's smallest step angle, laser beam divergence, optics dimensions, communication distance, and scanning area filling efficiency, etc. Furthermore, the optimization challenges of the transmit laser beam size considering the interplay among beam divergence, beam clipping, and scattering are studied in detail. This paper also presents the effect of laser peak power, initial beam size, and communication distance on effective communication beam width to maintain a long-distance (more than 100 km) communication with SNR ≥ 10 dB at a data rate greater than 500 Mb/s.
低地球轨道（LEO）中的立方星群是当今昂贵且庞大的卫星遥感系统的一个有吸引力的替代方案。本文介绍了实现立方星之间全向、高速、远程（超过100公里）数据通信的设计和优化规则。分析中考虑了立方星平台带来的前所未有的尺寸、重量、功率和成本限制以及商用现货组件的可用性。给出了与基于扫描镜的光束转向系统以及扫描镜最小步距角要求相关的分析研究。此外，我们展示了扫描镜最小步距角、激光束发散角、光学尺寸、通信距离和扫描区域填充效率等之间的关系和依赖性。此外，详细研究了考虑光束发散、光束裁剪和散射之间相互作用时发射激光束尺寸的优化挑战。本文还展示了激光峰值功率、初始光束尺寸和通信距离对有效通信光束宽度的影响，以便在数据速率大于500 Mb/s时保持与信噪比≥10 dB的长距离（超过100公里）通信。
