ARDLIB is a software library that provides a mission
independent interface to instrument-specific
calibration data. Tools such as `mkarf', `mkwarf',
`mkinstmap', `mkgrmf', and `mkexpmap' use this library
to compute effective areas, detector efficiencies, and
so on.
Currently the only mission supported by ARDLIB is Chandra. The
following Chandra instruments are supported:
- Mirrors: HRMA
-
Detectors: ACIS-[0-9], ACIS-I[0-3], ACIS-S[0-5], HRC-S[1-3], HRC-I
-
Gratings: HEG, MEG, LEG
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. For instance, an exposure map
representing the total amount of time spent observing
a point in the sky may be easily constructed by using
a uniform detector QE of 1.0 (e.g.,
detsubsys="ACIS-I3;QE=1;UNIFORM;CONTAM=NO") and a
mirror effective area of 1.0 (e.g.,
mirror="HRMA;area=1"). Qualifiers allow one to
specify these constraints in a simple way. Further
details on the use of these parameter qualifiers are
given in the help files for individual tools, such as
mkinstmap, which use the ARDLIB interface.
Generic qualifiers:
This option causes the calling program to halt with a
message specifying the options for the associated
parameter. For example, to get a listing of the
options for the `detsubsys' parameter of `mkarf', one
can use detsubsys="ACIS-S3;HELP" This causes `mkarf'
to exit, displaying a summary of the valid options for
the ACIS-S3 subsystem.
HRMA qualifiers:
| AREA=value |
|
| SHELL=n |
n=1,3,4, or 6 |
| BITMAP=xxxx |
x=0 or 1 |
For example, to specify HRMA shells 1 and 3, which correspond
to the bitmap "1100", use "HRMA;bitmap=1100". To compute using
a mirror area of 1, use "HRMA;AREA=1".
ACIS-S/I qualifiers:
| QE=value |
|
| UNIFORM |
forces QE to be uniform |
| CONTAM=yes|no |
if yes (the default), correct for
ACIS QE changes due to the buildup of
contamination on the optical blocking filter.
|
| IDEAL |
equivalent to "QE=1;UNIFORM;CONTAM=NO" |
| CHIP=value |
CHIP=4 means ACIS-4, which is also known as ACIS-S0 |
| WINDOW=xmin,ymin,xmax,ymax |
|
| REGION=BOX(xcenter,ycenter,xsize,ysize) |
|
| REGION=RECTANGLE(xmin,xmax,ymin,ymax) |
|
| BPMASK=value |
BPMASK=0 means ignore the bad pixel file |
| TIME=value |
Units are seconds since MJDREF |
By default, the time dependence of the ACIS QE, due to
the buildup of contamination on the optical blocking
filter, is accounted for automatically (CONTAM=yes).
The QE correction factor is computed for the
observation start time, TSTART, taken from the FITS
header. For more information
about the ACIS filter contamination model, see the
ACIS calibration web page at http://cxc.harvard.edu/cal/Acis/WWWacis_cal.html.
If the Observation Information file, e.g., obsfile as
specified in mkarf.par, has CTI_CORR=yes, then the
CALDB lookups will specify CTI-corrected files.
Note that "QE=xxx" affects the mean QE only; the QE
uniformities (QEU) are still applied.
Explicit use of the TIME parameter is normally
unnecessary because most tools automatically obtain the
observation time from the FITS header. However, if
necessary, this option may be used to specify
time-dependent instrument parameters such as the ACIS
QE. For example, to obtain the value of the correction
factor used to account for ACIS-S3 contamination in
observations carried out in Jan 2003, one may compute
an ARF using the detector subsystem parameter set to:
detsubsys="ACIS-7;QE=1;UNIFORM;TIME=1.57788e+08"
HEG, MEG, LEG qualifiers:
| SHELL=n |
n=1,3,4, or 6 |
| BITMAP=xxxx |
x=0 or 1 |
The SHELL and BITMAP parameters allow the computation of a
grating efficiency for the corresponding rings of the LETG or
HETG grating assembly.
HRC-S/I qualifiers:
| QE=value |
|
| UNIFORM |
forces QE to be uniform |
| IDEAL |
equivalent to "QE=1;UNIFORM" |
ARDLIB has many parameters that specify calibration
data for the various missions that it supports.
Currently, the only mission that is supported is
Chandra. If a parameter value is set to CALDB, the
library will query the calibration database (ie CALDB)
to find the best file: if you wish to specify a
specific file - such as the bad-pixel file that is
supplied for each ACIS observation - then you change
the parameter to point to that file. Further details
are available at the CIAO threads web page.
Directory containing data files
A colon delimited list of pathnames to search for
data files. If the first character of the string is
a `$', then the value represents the name of an
environment variable.
Effective area file
For generic mission support.
Vignetting file
For generic mission support.
AXAF eff-area file 0001
These parameters specify the name of the FITS file
and extension number for the on-axis Chandra HRMA
effective area for the appropriate shell. The
numerical suffixes specify the mirror shell as a
shell-bitmap. For instance, _0001 refers to shell
6, _0100 refers to shell 3, and _1111 refers to
shells 1,3,4,6.
AXAF vignet file 0001
These parameters specify the off-axis vignetting curves for the
mirror shells, as described above. The off-axis HRMA effective
area is represented as the product of an on-axis effective area
with the off-axis vignetting function.
ACIS-0 Mean QE File
These parameters specify the ACIS mean QE files for each of the
10 ACIS chips. The QE is given as the product of a mean QE with
the uniformity function. The values represented in these files
must include the filters.
ACIS-0 Uniformity file
These parameters specify the ACIS detector uniformity files for
each of the 10 ACIS chips.
ACIS-0 Bad Pixel File
These parameters specify the bad pixel files for each of the 10
ACIS chips. A value of "NONE" may be used if no data is
available.
At present, the ardlib does not support the use of
time-dependent bad-pixel files. This applies to the creation
of instrument maps for merged observations, when the number and
distribution of bad pixels changes between observations.
Typically the changes in bad pixels are small enough that a
single bad-pixel file may be used.
ACIS-0 Contamination File
ACIS-1 Contamination File
ACIS-2 Contamination File
ACIS-3 Contamination File
ACIS-4 Contamination File
ACIS-5 Contamination File
ACIS-6 Contamination File
ACIS-7 Contamination File
ACIS-8 Contamination File
ACIS-9 Contamination File
HRC-I Mean QE file
The HRC-I mean detector efficiency file.
HRC-I QE Uniformity file
The HRC-I QE Uniformity file.
HRC-S1 Mean QE file
These parameters specify the HRC-S mean QE files for each MCP.
HRC-S1 QE Uniformity file
These parameters specify the HRC-S uniformity files for each MCP.
HRC-S2 QE Uniformity file
HRC-S3 QE Uniformity file
HETG 1000 efficiency file
These parameters specify the HETG grating efficiency files for
the specified mirror shell bitmap.
HETG 0100 efficiency file
HETG 0010 efficiency file
HETG 0001 efficiency file
LETG 1000 efficiency file
These parameters specify the LETG grating efficiency files for
the specified mirror shell bitmap.
LETG 0100 efficiency file
LETG 0010 efficiency file
LETG 0001 efficiency file
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