How would a mission computer implement time-of-day and mission-time synchronization between subsystems for coherent logging?

How would a mission computer implement time-of-day and mission-time synchronization between subsystems for coherent logging?

• A. Time is synchronized via a single system-wide protocol but not all subsystems use it.
• B. Time is synchronized using a master clock and a protocol like PTP or mission heartbeat, with a common timestamp.
• C. Time is derived from random delays in communication.
• D. Use a master time source and synchronize via protocol (PTP/mission heartbeat); timestamp events with a common clock, and handle drift.

Answer: (D)

Maintaining a single, coherent time reference across all subsystems is essential for coherent logging. The best approach is to designate a master time source and continuously synchronize each subsystem’s local clock using a protocol such as PTP or a mission heartbeat. Every event is stamped with this common clock, so logs from different subsystems can be accurately correlated. Clocks drift over time due to temperature, hardware differences, and processing load, so the system must actively monitor and correct drift to keep alignment. This combination—a master time source, a synchronization protocol, common timestamps, and drift handling—provides robust, synchronized time across the mission computer network, enabling reliable event ordering and cross-subsystem analysis. Relying on a protocol that only some subsystems use would break coherence; deriving time from random delays offers no stable reference; and simply having a master clock with a protocol and a common timestamp without drift management risks long-term misalignment.

Maintaining a single, coherent time reference across all subsystems is essential for coherent logging. The best approach is to designate a master time source and continuously synchronize each subsystem’s local clock using a protocol such as PTP or a mission heartbeat. Every event is stamped with this common clock, so logs from different subsystems can be accurately correlated. Clocks drift over time due to temperature, hardware differences, and processing load, so the system must actively monitor and correct drift to keep alignment. This combination—a master time source, a synchronization protocol, common timestamps, and drift handling—provides robust, synchronized time across the mission computer network, enabling reliable event ordering and cross-subsystem analysis. Relying on a protocol that only some subsystems use would break coherence; deriving time from random delays offers no stable reference; and simply having a master clock with a protocol and a common timestamp without drift management risks long-term misalignment.