Behaviour of |${a_i}$| ratios at six virtual rover stations. Since all eight virtual rover stations exhibit similar characteristics, only the first (azimuth order) six are plotted. The circles connected by solid lines represent the ratios at each iteration and the dashed lines are the theoretical values. The values stabilize after 1–2 iterations. Not all Green's function components are equally important to reconstructing the final synthetic waveform; their relative importance depends on the specific earthquake source.