Figure 2. (a) The same data-acquisition grid as in Figure 1, but with source and receiver stations positioned at irregular, random coordinates. (b) Stacking fold. (c, d) Offset and azimuth distributions have minor outliers and are less erratic than the distributions in Figure 1. The data in (c) fit between values A and B in Figure 1c; the data in (d) fit below line C in Figure 1d.