The first step is usually to determine the efficiencies of antenna from sources of known flux. To do that, the SOLVE FLUX command forces SET AMPLITUDE SCALED. It uses all sources of known flux from the current index to compute the (time averaged) values of the efficiencies . The fluxes of other sources in the current index can then be determined using from the efficiencies. Sources of known flux are specified using the SET FLUX command. The sources should have been observed sufficiently closely in time to avoid any variation of the values. Also, good flux determination requires pointing errors to be similar on those sources.
The fluxes (measured or manually entered by SET FLUX) can be written to the output file using the STORE FLUX command.