FLatten map before making SNR mask COM.ZERO_SNR_HIPASS
"
com.zero_snr"
to be
based on a copy of the SNR map that has been high-pass filtering to remove structures larger than the
number of arc-seconds given by com.zero_snr_hipass. This will in general reduce the number of
source pixels in the mask. See also parameter "
com.zero_snr_ffclean"
. [0.0]