Plots of closure amplitudes at the X band of source 0016+731 as a function of GMST for three quadrangles, (a) GILCREEK–KOKEE–WETTZELL–NRAO85_3, (b) KOKEE–TSUKUB32–WETTZELL–YEBES40M, and (c) ISHIOKA–KOKEE–YEBES40M–WETTZELL. See Figure 5 for a description of the plot design. The structure-effect patterns in plots b and c can simply be combined because ISHIOKA and TSUKUB32 are two stations at the same site. The evolution of its structure effects is seen from the three plots.