There is a pressing need for accurate and reliable position, navigation, and timing (PNT) support on and around the moon; multiple space agencies have stated PNT as a requirement for upcoming missions. The first phases of lunar PNT focus on the lunar South Pole and low lunar orbit up to 100 km altitude. This paper seeks to provide insight into the primary contributions to positioning error on the lunar surface. To improve the estimations of performance, an alternative metric, user-equivalent range-error-weighted geometric dilution of precision (KDOP), is studied. The assumption that ranging error is constant across systems is shown to be invalid for candidate lunar PNT systems and leads to significant differences in performance estimation between KDOP and geometric dilution of precision, a commonly used measure. Parameters related to user error, onboard clock stability, and orbit determination performance are varied to find and quantify monotonic relationships between these design parameters and performance metrics. The metric KDOP is found to be needed for accurate performance estimation under reasonable technology performance assumptions.
Gabhart et al. (Tue,) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: