Hierarchical drift and excess scatter
Research context
research method · conditional · As of 2026-10-10
A network model can include per-instrument offsets, temporal drift, shared-reference effects and between-day variability alongside statistical noise.
Key knowledge
A network model can include per-instrument offsets, temporal drift, shared-reference effects and between-day variability alongside statistical noise. NIST's 2025 clock-network project describes hierarchical Bayesian ratio models for excess scatter. Such a random-effect component estimates a declared source of variability; it does not identify the physical cause of every unmodelled bias.
Conditions and scope
- Specify synchronization, epochs, covariance and prior information; ensure offsets and drift parameters are identifiable against a reference.
- Changing averaging interval or treating shared uncertainty as independent can give misleading precision. Validate new days/links and prior/model sensitivity.
Sources · 2
References
Sources retain their recorded scope. A source link alone does not establish verification of every statement.
Evidence and review
Inspected between-day excess scatter and hierarchical ratio-model account; project summary, not original experimental full text; source check dated 2026-10-10. Scope is limited to the cited statements, equations and assumptions, not the whole publication. Inspected §§8.5, 10.4–10.6, 11.4, 11.6–11.10, 12 and Annex B: shared effects, inverse calibration, time series and prior sensitivity; source check dated 2026-10-10. Scope is limited to the cited statements, equations and assumptions, not the whole publication.
2026-10-10 · Author source inspection of the displayed claim, model assumptions and equations; independent exact-content and branch-inventory review is a separate gate. Contemporary status is a dated snapshot, not a promise of ongoing monitoring.
Entry details
Permanent link to this entry ↗- Record identity
- research-measurement-network-drift-variation
- Revision
- research.1
- Structured reference record
- Postgraduate & research reference