Next: 18.42.3 Mosaics Up: 18.42 UV_STAT Previous: 18.42.1 /PLOT Contents Index
CASA and GILDAS handle the weighting scheme slightly differently and with different conventions for the Robust parameter values.
CASA uses only Briggs weighting, while IMAGER offers the Briggs weighting scheme (obtained for MAP_ROBUST < 0) and a different, more progressive, weighting (obtained for MAP_ROBUST > 0).
For MAP_ROBUST < 0, the corresponding CASA Briggs value can be obtained by adding 2.
In addition, CASA apparently uses a default value for the size of the UV cell in Briggs weighting which is about the dish diameter(*). If MAP_UVCELL is 0, IMAGER will use the same default value. Otherwise, IMAGER will use the specified user input.
(*) The default value quoted before is valid for a single field. However, the documentation is unclear in this respect and suggests that the UV cell size depends on the imaged field size. This would be strange, though. What happens for mosaics is even less clear.