Left panels: slice of the radial velocity map of a Lambert sphere rotating in the retrograde direction (solid-body rotation of 1 m s⁻¹ at equator), observed with a phase angle of ±40°. Radial velocities are measured on solar reflected lines. The width of the PSF used to degrade the image and radial velocity map is 35% of the planetary radius, which is equivalent to a 2-arcsec atmospheric seeing for Venus when it is observed at ±40° (see Fig. 9). The term δX refers to the apparent displacement of the planet on the sky caused by the atmospheric seeing.