Imu allan variance

1. How do you calculate Allan variance?
2. What is Allan variance used for?
3. How do you interpret Allan deviation?
4. What is Tau in Allan variance?

How do you calculate Allan variance?

Interpretation of value

Allan variance is defined as one half of the time average of the squares of the differences between successive readings of the frequency deviation sampled over the sampling period.

What is Allan variance used for?

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.

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 1 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 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.