Best-fit PSF centroid positions (full-markers) estimated on six meta-slices of ZTF18abqlpgq’s x, y, λ-cube during the first stage of the automated PSF extraction. Marker colors indicate the effective wavelength of the slice. Atmospheric differential refraction causes the true position of the target in the MLA to vary with wavelength. Our best model of this evolution is shown as open markers. This automated ADR parameter estimation allows us to predict the target centroid to an accuracy of a few percent of a spaxel.