Pointing Error Budget Development and Methodology on the Psyche Project

Quantum super-resolution with balanced homodyne detection in low-earth-orbit

“…However, in practice, finding the centroid and maintaining this position during the entire measurement time is very challenging on LEO satellites. For instance, B's pointing direction may fluctuate about the centroid or contain a fixed offset due to practical satellite pointing issues such as on-board mechanical vibrations [34][35][36]. Both fluctuating and fixed centroid misalignment issues would raise d min negatively impacting the precision of the BHD setup.…”

“…In figure 4 we perform the super-resolution check, d min < d rayleigh , on the example LEO setup with the constrained setting of N = 10 2 photons. We considered two cases of σ d , σ d /w 0 = 1 (realistic) and σ d /w 0 = 10 3 (worst-case) [36] with corresponding best and worst case for η. Our plot shows that superresolution is achievable over reasonable ℓ across all scenarios considered in our setup, and thus a fluctuating centroid issue may be tolerable in practice.…”

Beyond the Standard Quantum Limit in the Synchronization of Low-Earth-Orbit Satellites

“…Thus far our analysis assumes that B is perfectly aligned with an a priori known centroid that coincides with the weighted center of the two sources (weighted, for instance, by the relative brightness of each source). In practice, however, B's pointing direction may fluctuate about a true centroid and/or possess a fixed offset due to practical satellite pointing challenges [33][34][35]. Fluctuating and fixed centroid misalignment issues negatively impact the achievable d min in a BHD setup.…”

“…Evidently, when ℓ is sufficiently long, super-resolution is achievable for a large range of σ d that is well beyond the state-of-art in LEO satellite pointing stability (see for e.g. [35]). The BHD setup is therefore robust to a fluctuating centroid misalignment.…”