Outputs
The primary output product of MeqSilhouette is a CASA Measurement Set containing the complex visibilities, with all the user-requested corruptions applied to the data. The Measurement Set v2 specification can be found here. The tables and subtables in the MS are filled as follows:
The value of ms_datacolumn in the input JSON file must correspond to an existing column in the MAIN table. This column is filled with the corrupted complex visibilities.
The MODEL_DATA column is filled with uncorrupted visibilities. It is recommended not to set ms_datacolumn=’MODEL_DATA’ so that the uncorrupted visibilities are available to the user for later inspection.
The SIGMA column is filled with the standard deviation of the baseline-based complex visibilities computed using the SEFD. If mulltiple frequency channels are present, then SIGMA_SPECTRUM is also filled with these values.
The WEIGHT column is filled with inverse-variance weighting with the variance computed using the SIGMA values. If mulltiple frequency channels are present, then WEIGHT_SPECTRUM is also filled with these values.
The ANTENNA subtable is the same as the input antenna table pointed to by ms_antenna_table.
Optionally, there a few other outputs that MeqSilhouette can generate for recording the synthetic data generation process and verifying the contents of the MS.
The numerical values of all the Jones matrices are saved as numpy arrays.
A number of plots illustrating the properties of the complex visibilities and the various effects applied to them.
A preliminary image of the simulated data.
Export the MS into UVFITS format, for compatibility with other calibration packages such as eht-imaging and AIPS.