To use
for imaging simulations, first create a data set using
the `fakedata` procedure. This will create scans, for which one
can compute model values using `calcmodel` after reading a model
file. `calcmodel` will compute the complex visibilities (*scans.complexvis*) and squared visibilities (*scans.vissqm*). If one
wants to write this data into a FITS file, nothing needs to be copied
since the procedure `put_fits` uses the complex visibilities to
derive the FITS visibility variables amplitude and phase. If noise is
to be added to the visibilities, it should be added to the real and
imaginary parts of scans.complexvis.

The data can then be mapped in AIPS with or without using phase self-calibration.

Christian Hummel 2015-04-28