Top:radial velocity residuals by comparison with ground-based validation stars for single transits of the RVS focal plane (3 CCDs). Bottom: radial velocity performance for stars with ≥40 transitsas a function of magnitude, compared with ground-based standards. These spectra were taken in LR mode using the ecliptic pole scanning law. The systematic offset of 19.6 km s⁻¹ is an artefact of a 2-pixel offset for the LR wavelength scale with respect to HR in the processing, and should be ignored. The cause of the large residual for one star of V ~ 15 in this preliminary processing is unknown.