Acceleration equations are they in body or earth frame ?

[lct-tmr]

Hi. I am looking at the 3D equations of motion in the filter, and they are a bit buried in because they are packed together with the discretization, and I have a question about:

transferFunction_(StateMemberVx, StateMemberAx) = delta;
transferFunction_(StateMemberVy, StateMemberAy) = delta;
transferFunction_(StateMemberVz, StateMemberAz) = delta;

I think that this implies that:
v [k+1] = v[k] + a*dt
?

My understanding is that the liner velocity states StateMemberV* are in the body frame, and the linear accelerations perhaps as well (because of the way they are used as control, coming from a twist message).

In this case the equation for dv^b/dt should have extra term related to the rotational velocity, because the body frame is not inertial and dv^b/dt is not really a^b (inertial acceleration expressed in body frame):

dv^b/dt = - SkewSymmetrixForm[omega^b] v^b + (R^b_e)*a^e

or

dv^b/dt = - SkewSymmetrixForm[omega^b] v^b + a^b

best regards