Some instruments supported by ardlib allow the specification of
one or more qualifiers. The use of qualifiers allows the user
to influence the calculation performed by ardlib for the
corresponding instrument. To illustrate this point, consider the
mkinstmap program. It produces a 2-d image,
called an instrument map, that represents the product of the detector
QE with the mirror effective area, both which vary spatially. For
will generate an instrument map for the mirror-detector combination HRMA and ACIS-I3. Sometimes it is useful to generate an image of detector QE alone (showing any spatial non-uniformities). Rather than adding the logic to
mkinstmap mirror="HRMA" detsubsys="ACIS-I3"
mkinstmapto handle such special cases, the user may attach the
"area=1"qualifier to the mirror specification to cause ardlib to return a mirror effective area of 1.0 for that mirror, e.g.,
It is important to note that the use of this qualifier is totally transparent to
mkinstmap mirror="HRMA;area=1" detsubsys="ACIS-I3"
All instruments support the
"help" qualifier. This qualifier prints
out a list of qualifiers supported by the instrument. For instance,
results in the message:
mkinstmap mirror="HRMA;help" detsubsys="ACIS-I3"
Hence, to produce an instrument map for, say HRMA mirror shell 3, one may use
ARDLIB: Valid options for subsystem "HRMA" include: ARDLIB: SHELL=value Valid values are: 1,3,4,6 ARDLIB: BITMAP=value e.g., 1111 ==> all 4 shells ARDLIB: AREA[=value] (No value implies AREA=1)
It is important to understand that the only thing that
mkinstmap mirror="HRMA;shell=3" detsubsys="ACIS-I3"
"HRMA;shell=3"is that it represents a mirror and has an effective area associated with it. Ardlib handles the rest.