GNSStidsignaler

GNSStidsignaler are time signals broadcast by Global Navigation Satellite System satellites that enable receivers to synchronize to a precise reference clock. They are produced by multiple GNSS constellations, including GPS, GLONASS, Galileo, and BeiDou, each maintaining its own system-time scale and disseminating it through navigation messages and carrier signals.

The transmitted data include the offset and drift of the satellite’s on-board atomic clock relative to the system time, as well as time-of-week or time-of-day information and ephemeris data needed to determine the satellite's position. Receivers use these signals to estimate the receiver’s own clock error and align their locally generated time with the GNSS time scale. GNSS time is typically used as a primary reference for global time distribution and time transfer.

GNSS time scales are independent of Coordinated Universal Time (UTC); leap seconds are added to UTC but not to GNSS times. As a result, receivers often report both the GNSS system time and the offset to UTC, enabling accurate timekeeping and cross-system synchronization. The availability of multiple constellations and augmentation services enhances precision and resilience for time transfer.

Applications of GNSS time signals include network time synchronization for telecommunications networks, financial trading infrastructure, data centers, and critical industrial systems. Multi-constellation receivers and augmentation methods, such as satellite-based corrections, improve accuracy and reliability. Security concerns, including jamming, spoofing, and potential signal manipulation, drive ongoing improvements in anti-spoofing and authenticated services within GNSS ecosystems.