The number of correlation polarization products. For example (RR) this value
would be 1, for (RR,LL) it would be 2 and for (XX,YY,XY,YX) it would be 4, etc.
CORR_TYPE
An integer for each correlation product indicating the Stokes type as defined in
the Stokes class enumeration.
CORR_PRODUCT
Pair of integer for each correlation product, specifying the receptor
from which the signal originated. The receptor polarization is defined in the
POLARIZATION_TYPE column in the FEED table.
An example would be (0,0), (0,1), (1,0), (1,1) to specify all correlations between two
receptors.
FLAG_ROW
Row flag. True if the data in this row are not valid, but does not imply the
flagging of any DATA in MAIN.