Time and Standards - An Overview

Abstract

Have the frequency stability and accuracy reached a level of quality that exceeds needs in astrometry? This paper attempts to answer this question. After recalling current performances of time and frequency standards and their use in establishing time scales, the author considers their limitations in astronomical observations and studies. For expressing the value of almost all quantities, the accuracy of the frequency standards is sufficient. However, an improved stability could find applications in observation techniques, and the departure of realized time scales with respect to their theoretical counterparts is not negligible for some studies. The paper recalls the basic rule of quantity calculus and advocates its use despite its inadequacy to express difference of readings of time scales. In general, adherence to the metrological practice and the use of the SI may facilitate this work and its understanding by non-astronomers.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Mar 01, 2000
Accession Number
ADA435891

Entities

People

  • Bernard Guinot

Organizations

  • Paris Observatory, PSL University

Tags

Communities of Interest

  • Space

DTIC Thesaurus Topics

  • Abstracts
  • Accuracy
  • Ambiguity
  • Celestial Mechanics
  • Coordinate Systems
  • Ephemerides
  • Frequency
  • Frequency Standards
  • Instability
  • Intervals
  • Measurement
  • Metrology
  • Observation
  • Observatories
  • Solar System
  • Space Stations
  • Standards

Readers

  • Aerospace Test and Evaluation
  • Educational Psychology
  • Theoretical Analysis.