# Angular velocity in the state vector

Hi,

Just want to clarify what is the definition of the angular velocity in the state vector.

Is it the actual angular rates that are typically measured by the IMU's gyros in the IMU frame, or is it the derivative of the euler angles?

As it's known, these are not the same and I wanna make sure, since my IMU provides the first one but from the documentation it seems that the filter expects the second one.

Thanks