mwaf flag files
mwaf files indicate what visibilities should be flagged, and should be made
with Birli (which uses
AOFlagger). They aren't necessary,
but may improve things by removing radio-frequency interference. An example of
producing them is:
birli *gpubox*.fits -m *.metafits -f birli_flag_%%.mwaf
At the time of writing, hyperdrive only utilises mwaf files when reading
visibilities from raw data.
cotter-produced mwaf files are unreliable because
- The start time of the flags is not written; and
- The number of timesteps per mwaf file can vary, further confusing things.
Many MWA observations have pre-generated mwaf files that are stored in the
archive. These should be ignored and mwaf files should be made with Birli,
versions 0.7.0 or greater.