Maps of synthetic Doppler shifts (in m/s), computed assuming different wind models. In each panel, Venus’ disk is represented by the centered circle, the synthesized beam by the ellipse in the bottom left hand corner, and the terminator by the vertical arc. The contour step corresponds to 20 m/s. The Fourier-plane coverage of June 12, 2009, was used to simulate the observations. Top-left panel: prograde zonal wind model with V_eq = 69 m/s. Top-right panel: Bougher et al. (1986) SSAS wind model with V_ter = 200 m/s. Bottom-left panel: Bougher et al. (1986) SSAS wind model with V_ter = 200 m/s, combined with a V_eq = 100 m/s RSZ wind, localized in an equatorial band. Bottom-right panel: same model as in bottom-left panel, but with a modified SSAS wind velocity field in the day-side varying as , where sza is the local solar zenith angle (solar incidence).