Simplified schema of the reference observing sequence (ROS) in the four dithers for the VIS and NISP channels. At the beginning of each dither VIS and NISP-S observe simultaneously after the Filter Wheel Assembly (FWA) movement and few seconds to allow the telescope to stabilise. After the exposure, the Grism Wheel Assembly (GWA) movement lets the light pass for the filter observations of J_E, H_E, and Y_E, denoted as JHY in red in the figure. In the meantime, the VIS instrument will perform the readout and processing of the acquired mosaic image. The first dither includes an additional short VIS exposure while the last dither ends with a brief flat field frame.