Example of a model requiring a multi-peak fitting technique. Left: fit comparison: naïvely fitting the model V_fit(u; d) (Eq. (33)) to the visamp profile |V(u)| (solid red curve) yields an excellent but suboptimal fit (dashed yellow curve), since a better one exists (dashed black curve). Right: goodness of fit g(d_φ) as a function of fitting diameter (Eq. (36)). The absolute best-fit corresponds to the global maximum of g(d_φ), while other local maxima correspond to good but subopitmal fits. These peaks are approximately periodic with a separation Δd_φ ≈ 0.2 μas that exactly matches 1/u_w, since our baseline window is at u_w ∼ 1000 Gλ.