In march the SLSTR format will be updated regarding an improvement for the F1 channel registration. The format change consists of adding a fifth SLSTR image grid (labelled ‘fn’ and ‘fo’) with a 1 km resolution and only dedicated to F1 channel. The SLSTR L1B reader will be updated as described in https://senbox.atlassian.net/browse/SIIITBX-203#icft=SIIITBX-203 . In consequence, it must be ensured that the PDU Stitching Tool can stitch files that have this format change.