# Torque induced regular precession/ nutation calculation and visualization out of attitude Data

I have a rocket body with given Euler Angles, Quaternions and Angular-Velocities for given time steps. And I'd like to calculate the regular precession and nutation for every time step, so that I can plot the cange of Nutation-Angle over time.

Roll, pitch, yaw and Quaternions are given in inertial-frame, while Angular velocity is given in the Body-Frame.

For some reason I read that the nutaion-angle is simply the given pitch. But I am not sure if that is really the angle I am looking for because the values dont seem to fit my prediction.

I'd like to also plot the precession. So that it looks something like this

Thanks for all suggestions.

• And your question is? You don't show any data so we cannot make any suggestions for analysis, you don't show how you calculate any result so we can't comment there. Aug 28 '19 at 10:58

So what you want to do is figure out how to express the nutation of the body about the average precessional vector. At this point, we need to know the specific Euler angle system you are using. Is it a true Euler system, or is it a Tait-Bryan angle set? According to this document (p 473) - http://adsabs.harvard.edu/full/1992AREPS..20..469M, the conventional way to represent nutation is with two angles - $$\Delta\epsilon$$, the obliquity perturbation; and $$\Delta\psi$$, the longitude perturbation.