Evaluation Board User Guide
UG-154
Rev. 0 | Page 11 of 16
NOISE AND ROOT ALLAN VARIANCE PANEL
09113-
020
Figure 20. Noise and Root Allan Variance Panel
The software GUI includes the ability to calculate and plot the
root Allan variance (RAV) of the ADXRS800. Root Allan
variance can be approximately described as the variation of
successive long-term averages of the null output of the
ADXRS800. This is usually reported in units of degrees per
hour and indicates the long-term bias stability of a gyroscope.
To generate an accurate root Allan variance plot, it is
recommended that this test be run (at least) overnight, during
which time care should be taken to ensure that the device is in a
temperature-stable, and disturbance-free environment. Any
rotational rate input into the gyroscope can greatly degrade the
validity of the resulting RAV plot.
Determining the rms noise of the ADXRS800 can be done on
this same panel. The evaluation GUI calculates the rms noise by
taking the standard deviation of the specified number of points,
which is roughly equivalent to the 1 sigma peak-to-peak noise
value. These data points are obtained at a 500 Hz data rate. It is
recommended that you perform this test with at least 16,000
data points to obtain accurate results. Fewer data points can be
used, but the reported rms noise is then subject to higher
variability.
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
