Tomographic cosmic shear signal (presented here only for ξ₊) measured by DES Y1 (black curve) and compared to the expected signal introduced by the spatial correlations of astrometric residuals due to the atmosphere by rescaling HSC data on 30 s LSST exposure (blue area). If not corrected, the effect of astrometric residuals in LSST on galaxy shapes will bias the shear signal. This is a lower limit as the HSC site is at a higher altitude that the Rubin Observatory and the effective size mirror of HSC is bigger than the Rubin Observatory telescope. With the GP correction proposed in this current analysis, we expect to be able to lower it by orders of magnitude.