Editing Allan variance (section)

===''τ'' bias function===
While formally not formulated, it has been indirectly inferred as a consequence of the ''α''–''μ'' mapping. When comparing two Allan variance measure for different ''τ'', assuming same dominant noise in the form of same μ coefficient, a bias can be defined as

:<math>B_\tau(\tau_1, \tau_2, \mu) = \frac{\left\langle\sigma_y^2(2, \tau_2, \tau_2)\right\rangle}{\left\langle\sigma_y^2(2, \tau_1, \tau_1) \right\rangle}.</math>

The bias function becomes after analysis

:<math>B_\tau(\tau_1, \tau_2, \mu) = \left( \frac{\tau_2}{\tau_1} \right)^\mu.</math>