Session
Technical Poster Session IV
Location
Utah State University, Logan, UT
Abstract
Present and future demand for global, low-latency telecommunications gives rise to several proposed constellations of satellites in Low Earth Orbit that feature high-bandwidth optical network links between spacecraft.
Free-space optical communication between satellites on separate orbital planes is a non-trivial endeavor. Over long distances, the budget for pointing error is very restricted. To illustrate the scales involved, this paper begins with a quantitative examination of angular inter-satellite vectors. This establishes context for the subsequent presentation of relevant design, integration, and on-orbit considerations that affect the ultimate performance of extremely precise pointing and tracking systems.
Coarse pointing precision plays a substantial role in the link acquisition sequence, but opto-mechanical considerations are often underestimated. This can lead to trade studies that result in higher divergence and higher power acquisition systems. Adequate design of coarse pointing assemblies (CPA), leading to superior boresight accuracy, can relieve the pointing requirements on fine pointing assemblies (FPA). With lower FPA range requirements, similar dynamic range capabilities of FPA sensors result in higher resolution beam pointing. CPA precision trade studies will be performed on realistic inter-satellite link angles to examine error sources and highlight pitfalls.
Paper for Precision Pointing Considerations for Long-Distance Free-Space Optical Communications
Precision Pointing Considerations for Long-Distance Free-Space Optical Communications
Utah State University, Logan, UT
Present and future demand for global, low-latency telecommunications gives rise to several proposed constellations of satellites in Low Earth Orbit that feature high-bandwidth optical network links between spacecraft.
Free-space optical communication between satellites on separate orbital planes is a non-trivial endeavor. Over long distances, the budget for pointing error is very restricted. To illustrate the scales involved, this paper begins with a quantitative examination of angular inter-satellite vectors. This establishes context for the subsequent presentation of relevant design, integration, and on-orbit considerations that affect the ultimate performance of extremely precise pointing and tracking systems.
Coarse pointing precision plays a substantial role in the link acquisition sequence, but opto-mechanical considerations are often underestimated. This can lead to trade studies that result in higher divergence and higher power acquisition systems. Adequate design of coarse pointing assemblies (CPA), leading to superior boresight accuracy, can relieve the pointing requirements on fine pointing assemblies (FPA). With lower FPA range requirements, similar dynamic range capabilities of FPA sensors result in higher resolution beam pointing. CPA precision trade studies will be performed on realistic inter-satellite link angles to examine error sources and highlight pitfalls.
