The importance of pointing and tracking is demonstrated with current deep-space optical communications system concepts. Maximum Likelihood (ML), Minimum Square Counting Error (MSCE), and Maximum Product (MP) estimation algorithms (or decision rules) are derived to estimate the location of the receiving station to sub-pixel resolution. Comparisons of the above algorithms are made, via Monte Carlo computer simulation, in terms of estimator's bias and variance. Optical communication link analyses are made for a typical Earth-Mars scenario, to gain engineering insights. It is observed that both the ML rule and the MSCE rule perform better than the MP rule.
Moe Zaw Win,
"Estimation And Tracking For Deep-Space Optical Communications", Proc. SPIE 1059, Space Sensing, Communications, and Networking, (2 June 1989); doi: 10.1117/12.951698; https://doi.org/10.1117/12.951698