Overlapping Allan Deviation Calculator
Calculate overlapping Allan deviation from equally spaced fractional-frequency observations.
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Result
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Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Compare every adjacent pair of m-sample mean windows, including overlapping start positions.
OADEV²=Σ(mean next m−mean previous m)²/[2(N−2m+1)]
Worked example
For m1 and fractional offsets0,1e−9,0, the Allan deviation is1e−9/√2.
Assumptions and input details
Gap-free equal-duration fractional-frequency averages, not phase samples. No drift removal, dead-time correction, noise classification or confidence interval. Need at least2m observations.
References: NIST: stability analysis handbook
Unit definitions
Unit selection is independent of language. Each selector contains only units for its physical quantity. Calculations use defined base units internally.
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
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