Some of the images produced at different steps in the DD self-calibration loop implemented as Algorithm 1. The maps correspond (from left to right, top to bottom) to Steps 1.1, 1.8, 1.12, and 1.18, respectively. The white lines show the facet locations. The color scale is the same on all panels and is displayed using an inverse hyperbolic sine function to render both the low level artifacts and some bright sources.