Differences in parallax between the baseline primary solution and a special validation solution where the data are split into early and late observations (within the AF). a) Baseline minus late. b) Baseline minus early. c) Late minus early. Median differences are shown in cells of about 3.36 deg². The maps use an Aitoff projection in equatorial (ICRS) coordinates, with origin α = δ = 0 at the centre and α increasing from right to left.