Specify which input data is used to compute the model visibilities: Clean Component Table (CCT), Clean image (IMAGE) or UV_FIT results.
By default, the UV_MODEL output UV data takes its Frequency from the input Image or CCT data set. However, this can be supersed by the optional argument Frequency, which can take the value IMAGE (the default), UV or any frequency in MHz.
If not specified with /MODE, the Mode is derived from the last executed operation (CLEAN or UV_FIT)
The SELF mode is used for Self-Calibration by the SELFCAL command. It uses a Clean Component model from the deconvolution of the image produced by UV_SELF, to be later applied in the iteration process.