output_format format
where format is either ascii (default) or flexstor.
Note that flexstor does not currently work when umu and/or phi is specified.
There is also the
possibility to write uvspec simulation results to an existing netCDF file. For
that format must be netCDF and the option output_file must be given
and point to a file that contains a lat/lon/time grid.
If format is set to sat picture then output_file must be given and point
to a NetCDF-File that contains a pixel x/pixel y/time grid.