The param_file may contain lines with commands:
Keyword=value

Settable parameters are:

      Description        Keyword       Units/Values

      Project name       PROJECT          
      Rest frequency     RESTFRQ       MHz
      Observing mode     OBSMODE       sou|ref|bmsw|frsw
      Frequency offset   FRQOFF        MHz
      Reference position REFPOS        radec/azel
      X offset           RALFA         deg
      Y offset           RDELTA        deg