### 4.2.2 Angular Velocity Estimation

The angular velocity estimate describes the current rotation
vector of the vehicle. This is described in vehicle coordinates. No
further processing is requires. Data from the three axis angular rate
sensor is transformed into vehicle frame as described in Section
2.4.1. The sensor bias estimate is then subtracted (Section 4.3.2).
Finally, the signal is processed by a simple first order digital
filter (Section 4.3.1).