An improved yaw attitude model for GPS Block IIF satellites during eclipse seasons

Abstract This study improves the operational eclipse-season yaw attitude model for Global Positioning System (GPS) Block IIF satellites by using Reverse Kinematic Precise Point Positioning (RKPPP) yaw estimates as an observation-driven reference. Using a 7.5-year global GPS tracking dataset, we reconstruct yaw attitude time series over eclipse season maneuvers and compare them with the current operational attitude model. The comparison reveals four recurring discrepancies. Three occur during noon turns: (1) occasional rotation direction mismatches, (2) an inconsistent pre-eclipse yaw evolution that introduces an abrupt change in rotation direction at maneuver onset, and (3) an apparently premature maneuver initiation reflected by large yaw differences. The fourth discrepancy occurs during midnight turns when the $$\beta$$ β angle is close to zero, for which the modeled rotation direction differs from that inferred from RKPPP. To address these issues, we introduce a satellite-specific $$\beta$$ β bias rule for the noon-turn and apply an empirical modified $$\beta$$ β angle prior to eclipse entry to adjust the yaw rate and delay the maneuver onset. For midnight turns at small absolute $$\beta$$ β angle, we propose a decision rule based on the signs of the $$\beta$$ β angle at maneuver start and the $$\beta$$ β rate. When implemented in network orbit and clock estimation, the revised model reduces phase-residual signatures associated with attitude maneuvers and yields smoother, more consistent satellite clock estimates around yaw turns.