UT are shown. The IPP belonging to the CALLISTO BIR antenna locates in the wide valley (grey plus) between the crests C1 and C3. The IPP pertaining to the CALLISTO GLASGOW antenna is in the valley (grey asterisk) between the crests C2 and C3, closer to the former. In panels (a) and (b), this time corresponds to the moment right after the onset of the SC-G(II), while the SC-B(II) has lasted almost half of its lifetime by then. The SC-B(II) ends at 10:21 UT. The SC-G(II) disappears later near 10:24 UT. The respective IPPs, corresponding to these time moments, have reached the crest C3, and as a result, the focusing action of this TEC perturbation was completed (see the animation in Figure 4). Visually, the SC-G(II) and the SC-B(II) differ more than the previous pair. Nevertheless, the performed analysis of the dTEC maps confidently confirms their common origin. The computed spacing between two tracks of IPPs at the 250-km height is about 370 km. The distinctions in spectral shapes of the SC-G(II) and the SC-B(II) might have arisen from variations of the focusing conditions such as magnitude of electron density, height and width of TID layer, spatial structure of valley 