Keywords: mrtcal-prog-manual

Next: Reading the DATA column Up: Chunks and chunksets Previous: Chunks slicing Contents

# Polarimetry

The presence of polarimetric measurements in the IMBFITS file is described in the `POLAR` column of the `BACKEND` table. For a non-polarimetric scan, all the chunks in the `POLAR` column have the `NONE` value. For a polarimetric scan, values can be `NONE`, `AXIS`, `REAL` or `IMAG` (note that non-polarimetric chunks -`NONE`- can be mixed with polarimetric ones).

In addition, calibration scans for polarimetric measurements must provide a `calGrid` subscan. It absent, MRTCAL will mark this scan failed as it can not be used to calibrate polarimetric science scans.