Model-fitting results of the kinematic features for knot C28 including trajectory, core separation, coordinates, apparent velocity, viewing angle, Lorentz factor, and Doppler factor. In the first panel, the green and blue lines represent the fitting model trajectories calculated for precession phases ω ± 0.63 rad. In the 6th panel, the green and blue lines represent the precessing common parabolic trajectories calculated for precession phases ω ± 0.63 rad. In the last two panels, the relations of the knot’s position angle vs. core separation and vs. time are shown.