Comparison of profile fitting of Gaussian and PSF models in the uυ-plane and the image plane. Top: relative difference between recovered and input parameters of flux density (left), size (middle), and axis ratio (right). The recovered parameters were obtained from fitting with an elliptical Gaussian (orange), a circular Gaussian (green), and a point (blue) source model using uv_fit (open symbols) and galfit (solid symbols). Bottom: similar to the top panels, but we plot the ratio of measurement uncertainty derived from galfit in the image plane to that obtained from uv_fit in the uυ-plane. The measurement uncertainties are estimated as σ = 1.48×MAD.