Example of the GW signal from one of the simulations and how it appears in the astrometric solution. The black curve (δ𝑔_p) is the AL component of the GW signal in the preceding FoV. The red dots (R_p) show the AL residuals of the solution in the same FoV. For comparison, the red curve shows half the differential GW effect, (δ𝑔_p − δ𝑔_f)/2. All data are normalised by ∆_max. The frequency of the GW signal was ν = 101.160 nHz, equivalent to a period of P_gw ≃ 114.42 d.