The `one channel' in the title of this sub-section might refer to a channel 0 visibility file or a single channel from a multi-channel visibility file. This, the simplest of all cases, can be dealt with by the task HORUS, which can operate directly on the multi-source file. Alternatively, you could split off a calibrated single-source file with SPLIT (see § 12 above), and image it with either HORUS, UVMAP, or MX. If you have concatenated data from different observing runs, then you probably already have a single-source file with the calibration applied (see § 14).