bearing vector error-state time derivative

[stihuangyuan]

thanks for your great work. but i have some question about imu propagate F G matrix.
for bearing vector error-state time derivative how could i compute it?

d (\delta u) / dt = d(u_t)/dt - d(u)/dt
u_t and u express true state and nominal state, and then use u time derivative.
or
\delta u = N(u)^T Log(R_t R^T)
and then compute it time derivative

[bloesch]

I am not exactly sure what you mean. All Jacobians in Rovio are not derived via error-state contemplation but by directly computing derivatives on the manifold. Ultimately, both should lead to the same results.