(Georgia Institute of Technology, 2017-04-08)
Dahl, Trevor A.
This study evaluates pointing requirements for free space optical data links of a
satellite network. For many applications, optical links pose a distinct advantage over radio
frequency (RF) links for their far higher data transmission rates. They can also be much
lighter than RF antennas and require far less power, making them ideal transmission
methods for small satellites and CubeSats. While more power efficiency is achieved thru
narrow beam divergence, the narrower beams pose a technical challenge due to the higher
pointing accuracy required for effective transmission. A general method for characterizing
pointing tolerance, angular rates and angular accelerations for Line-of-Site (LoS) vectors is
devised. Several case studies involving different (single-layer) constellation designs were
evaluated. Varying degrees of inclination and offset of true anomaly from one plane to a
connecting plane were evaluated and corresponding angular velocity and accelerations are
reported. The study finds that the methodology outlined gives crucial information to assess
pointing requirements against various constellation designs. This assessment can then drive
the trade space for designs for optically linked networks from the hardware aboard each
satellite, to the design of the satellite constellation itself.