## Line results: Motions |

Acceleration, GX acceleration, GY acceleration, GZ acceleration

Available at nodes. The magnitude and components, with respect to global axes, of the velocity and acceleration of the node, relative to earth.

x acceleration, y acceleration, z acceleration

Available at nodes. The components, with respect to the node axes directions, of the velocity and acceleration of the node, relative to earth.

Warning: | If velocity or acceleration are not logged, then the corresponding results are derived by numerically differentiating the logged positions of the node with respect to time. The accuracy of the results will therefore depend on the log sample interval. If the log sample interval is large, then the results will not show higher frequency components of velocity and acceleration; if it is small, then results may be inaccurate due to loss of precision in subtraction. |

Available at nodes. The magnitude and components, with respect to the node axes directions, of the acceleration vector, $\vec{a}$, of the node, relative to the vertically downwards acceleration due to gravity, $g$. That is, these results report the vector $\vec{a} - g\vec{Z}$.

This relative acceleration can be thought of as the acceleration of the node relative to the free-falling state. This is the acceleration that would be reported by an accelerometer attached to the node (since an accelerometer reading of zero corresponds to free-falling), with its measurement directions aligned with the node axes directions.