Evolution of the NoRH wave derived from the 17 GHz stack plots shown in Fig. 4 (Koshix algorithm). Top: kinematics of the leading edge and the wave peak. Also shown are second-degree polynomial (red lines) and power-law fits (blue lines), and the corresponding mean acceleration a and the power-law index δ is indicated. For comparison, the leading edges of the Hα (red triangles) and EIT wavefronts (green diamond) are shown as well. Middle: evolution of the wavefront width (FWHM). Bottom: evolution of the perturbation amplitude, ΔT_b.