(u, v)-coverage of our observation at 1.68 GHz: full observation with ground+SRT (left) and ground-only array (right). Different color shows the ground stations providing the baseline with the SRT (see Table 1 for station codes). The maximum baseline length of space-baseline (∼5.6 D_⊕) and ground-baseline (∼1 D_⊕) are shown with broken line circle, which correspond to the angular resolution of ∼530 μas and 3 mas respectively. Each point has been averaged with 5 min interval.