Backup Hydrogen Maser Steering System for Galileo Precise Timing Facility

[摘要] Two hydrogen masers (HMs) are used in the Precise Timing Facility to provide the physical realization of Galileo System Time, insuring the extremely high short-term stability required for the navigation functions.In order to allow a smooth switch over between backup and primary HMs, the “backup HM steering algorithm” is developed.This acquires the phase difference measured between two HMs, computes a steering correction, and generates the steering correction to the backup HM via a PicoStepper with a 0.1-picosecond resolution. The algorithm design is based on outlier removal and a proportional-integral filtering controller. To verify the steering operability and the loop performance, the overall backup HM steering system is simulated using real HM-HM measurements, andwith simulated anomalies (phase/frequency spikes, jumps, and drift).

[学科分类] 电子、光学、磁材料