Comparison of the radial velocity maps of mock catalogues from the K6 simulation with observational errors of Gaia (DR4 and DR5, top row) and GaiaNIR (M10 and L10, bottom row). All maps are shown in the LMC in-plane (x′, y′) Cartesian coordinate system and zoomed-in to the centre co-ordinates to show the bar signature. Black contour lines separate the overdensities (bar and spiral arms) from the underdensities.