Multi-transit analysis receives single-transit radial velocities and their uncertainties from STA (see Section 6.4.7). The STA Gaia-centric radial velocities are converted to barycentric by adding their barycentric radial velocity correction, which can range from $+30$ km s${}^{-1}$ to $-30$ km s${}^{-1}$ as a function of Gaia’s six hour revolution (Figure 6.6).

The ${V}_{\mathrm{rad}}$ uncertainty provided in Gaia DR2, is given by Equation 6.2, where $N$ is the number of transits used to obtain ${V}_{\mathrm{rad}}$. $N$ is also provided in Gaia DR2.