Skip to main content

NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.

Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.

U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Theo1 Confidence Intervals

Published

Author(s)

T Tasset, David A. Howe, Donald B. Percival

Abstract

Theoretical variance #1 (Theo1) has been developed at NIST to improve the estimation of long-term frequency stability. Its square-root (Theo1-dev) has two significant improvements over the Allan deviation XX called ¿Adev" in estimlating long-term frequency stability in that (1) it can evaluate frequency stability at averaging times 50 % longe'r than those of Adev and (2) it can estimate frequency stability with greater confidence than any other estimator. We discuss a method for determining the exact confidence intervals of Theo1, particularly useful for small sample sizes, using analytic techniques. The confidence intervals of Theo1 are narrower and less skewed ( more symmetric) than confidence intervals based on chi-square.
Proceedings Title
Proc. IEEE Intl. Ultrasonics, Ferroelectrics, and Frequency Control Anniversary Joint Conf.
Conference Dates
August 23-27, 2004
Conference Location
, USA
Conference Title
IEEE Intl. Ultrasonics, Ferroelectrics, and Frequency Control Conf.

Keywords

Allan variance, Chi-square, confidence interval, distribution function, frequency stabilization, frequency standard, Theo1, TheoH

Citation

Tasset, T. , Howe, D. and Percival, D. (2004), Theo1 Confidence Intervals, Proc. IEEE Intl. Ultrasonics, Ferroelectrics, and Frequency Control Anniversary Joint Conf., , USA, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=50161 (Accessed October 10, 2025)

Issues

If you have any questions about this publication or are having problems accessing it, please contact [email protected].

Created August 22, 2004, Updated October 12, 2021
Was this page helpful?