rgsregions
adds the source and background extraction region
extensions to the source list. For each relevant source position
there is one region in the spatial plane and one region per
(specified) reflection order in the energy plane. The relevant
source positions refer to the sources marked for processing. The
spatial background region covers the entire exposed surface of the
focal plane, except for a buffer zone around the position of each
source marked for exclusion. Note that the source selections (for
processing and exclusion) are determined by the procsrcsexpr
and exclsrcsexpr parameters and recorded in the
SRCLIST table as selection flags. To sanction the existing
settings of these flags supply empty strings for these parameters. A
spatial background region cannot be defined for HTR mode data; there
is instead a set of order-specific background regions in the energy
plane for each selected source.