(u, v) coverage of our observation at 22 GHz. Left: ground-only array. Right: full observations with ground-based arrays plus the SRT. Different colors show the ground stations providing the baseline with the SRT (see Table 1 for station codes). The maximum baseline lengths of the space baseline and the ground baseline are shown with dashed circles, which correspond to angular resolutions of 47 μas and 220 μas, respectively. Each point has been averaged with a 2-minute interval in both panels.