ThêoH Bias-removal Method

• Published in: 2006 IEEE International Frequency Control Symposium and Exposition pp. 788 - 792
• Main Authors: Howe, D.A., McGee-Taylor, J., Tassett, T.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01-06-2006
• Subjects: Clocks; Frequency estimation; Frequency measurement; Humans; NIST; Optical noise; Phase noise; Stability; Statistics; Switches
• ISSN: 2327-1914
• DOI: 10.1109/FREQ.2006.275488

A version of Theol variance, called TheoBR variance (BR for "bias-removed" relative to the Allan variance), is constructed. This relative bias correction is applied over a range of the longest recommended Allan r values for a given data run. TheoH deviation ('H' to indicate a hybrid combination of TheoBR, and Allan deviations) is the Allan deviation in short term and switches to the TheoBR, deviation in long term. In the presence of non-integer-power-law and mixed noise types, the approach is as effective and less cumbersome than past approaches, and requires little, if any, a priori knowledge or human judgment of data being analyzed. The substantially gained properties of Theol at large r, to 50 % beyond the longest possible r using the Allan deviation alone, can be obtained without Allan bias. Long-term frequency stability can be obtained in essentially one-third less time. For example, a two-month stability can be obtained with three months of data, rather than the four months of data that are usually required for such a point