Figure 1.

(a) Spherical coordinate systems centered at each location, (ϕ^l, θ^l), and world coordinates, (ϕ^w, θ^w), for defining source trajectory. (b) Example great circles of different o sets and amplitudes in (ϕ^l, θ^l). (c) Metal creating “gaps” in (ϕ^l, θ^l) for two example locations in (a), resulting in incomplete sampling when an orbit intersectings both “gaps”.