How to interpret Allan Deviation plot for gyroscope?

1. How do you interpret Allan deviation?
2. What are the units of Allan deviation?
3. What is Allan variance and how is it used?
4. What is Tau in Allan variance?

How do you interpret Allan deviation?

An Allan deviation of 1.3×10−9 at observation time 1 s (i.e. τ = 1 s) should be interpreted as there being an instability in frequency between two observations a second apart with a relative root mean square (RMS) value of 1.3×10−9. For a 10-MHz clock, this would be equivalent to 13 mHz RMS movement.

What are the units of Allan deviation?

Allan Deviation is a unitless measure of stability, typically used to quantify the stability of clocks and other oscillators.

What is Allan variance and how is it used?

Allan variance is a statistical analysis tool for identifying various noise types that exist in a signal. Developed in the mid-1960s, the Allan variance was used to measure the frequency stability of precision oscillators. Later, this technique was applied to other areas as well.

What is Tau in Allan variance?

Allan variance is used to measure the frequency stability of oscillation for a sequence of data in the time domain. It can also be used to determine the intrinsic noise in a system as a function of the averaging time. The averaging time series τ can be specified as τ = m/fs.