Robust Vector Tracking for GNSS carrier phase signals

A new formulation of a robust vector phase-locked loop (VPLL) for joint tracking of carrier phase from the navigation satellites is presented. This partitioned tracking method leads to an increased tolerance to unmodeled or unexpected disturbances in the carrier phase tracking, providing a trade off between the pure VPLL and the classic scalar tracking loops. It also provides a solution for smoother transitions between scalar tracking and vector tracking operation modes, which can be of importance in more difficult environments, where the bias estimation may not cope with the fast changing dynamic, leading to harsh transitions and possibility of phase lock loss or inaccurate results.