STSDAS Version 3.7 Release Notes
15 June 2007
This release of STSDAS contains changes to
ACS, AXE, CALSTIS, CALWP2, MultiDrizzle, PyDrizzle, SYNPHOT, and MSTOOLS as well
as minor changes to CVOS and HSTIO.
One new task has been added; namely,
-
rnlincorr (HST_CALIB/NICMOS; PyRAF only)
The specific changes are detailed in the
following sections.
Platform Support
Binaries
for this release were built on Red Hat
Enterprise Linux 3, Solaris 5.8, and Mac OS X 10.4 (PPC and Intel architecture).
Binaries for macintel were built and require iraf 2.13.beta from
http://iraf.net.
HST_CALIB
CALACS 4.6.3
CALACS was updated to Version 4.6.3 (14-Dec-2006).
Bugs fixed in this version include:
-
Problems recognizing wild-card values in the BPIXTAB keyword value were
corrected so that the hot pixels will be flagged correctly in SBC data.
AXE
AXE was updated to version 1.6. See
the
official aXe site for details related to this update.
NICMOS
SAAclean:
-
The NICMOS team at STScI is seeking feedback on users' experience
with this task in calibrating NICMOS data. Please contact help@stsci.edu if
you have used this task in the course of your science.
-
The task was converted to use the numpy array package, rather than numarray
and Numeric. The linear algebra routines from the ScientificPython package
were consequently updated.
rnlincor:
-
RNLINCOR is a new task that corrects for countrate-dependent nonlinearity in
NICMOS data. The nonlinearity constants depend on the camera/filter
combination; it is obtained from the *_nlz.fits file available in CDBS nref,
and stored in the header keyword RNLCALPH in the primary header of the
output file. The zeropoint corrections (PHOTFNU/PHOTFLAM) are also updated.
The algorithm used by this task is described in the NICMOS ISR 2006-003 by
de Jong.
-
This task is written in python and is available only under PyRAF.
STIS
This release contains CALSTIS Version 2.24
(23-May-2007)
and represents the calibration to be used for the final reprocessing of all STIS
data taken prior to SM4.
The following bugs were corrected:
-
Failures of CALSTIS4 arising from "invalid floating point operation"
exceptions with echelle data.
-
CALSTIS tried to process wavecal exposures even if they had exposure time of
zero, leading to invalid offsets.
-
CALSTIS tried to process science exposures that had exposure time of zero,
which failed with a divide by zero error during flux calibration.
-
There was a bug in CALSTIS in the BLEVCORR step for CCD data, which resulted
in a small offset (of order 0.005 DN).
-
SDQFLAGS added a new flag (NOT_CTI_CORR) for pixels that have a gross counts
less than or equal to 0 when cticorr= PERFORM.
-
ODELAYTIME: a new function was written to derive the FIRSTMJD value from the
EPHMSTRT keyword in the primary header if the FIRSTMJD value is not found in
the parameter ephemeris.
-
STISNOISE was incorrectly updating the fwhm parameter due to an
uninitialized variable.
-
WX2D: Changes were made to improve the speed by using array operations when
possible.
The code has seen a number of small, additional improvements related to
maintainability but otherwise not affecting the algorithms or accuracy. A help
file for MKTRACE was added.
WFPC2
CALWP2 has been updated to Version 2.3.0
(May 24, 2007) in this release. This new version applies the correction to
WF4 data affected by the low-bias readout problems. This support includes:
-
Adding support for a new reference file required for this new calibration
step: WF4TFILE
-
Adding support for a new calibration switch for this new calibration step:
WF4TCORR
-
The reference file, WF4TFILE, also includes a keyword which specifies the
low bias level limit: WF4TBDQ
-
The bias values reported in WFPC2 headers now include both uncorrected and
corrected values, with the uncorrected values reported in the new BIASEVNU
and BIASODDU keywords for each chip.
This new calibration step corrects WF4 data for low bias levels, and flags all
the pixels in the WF4 DQ array with a value of 2048 when the original
(uncorrected) bias levels fall below the threshhold speecified in the reference
file's WF4TBDQ keyword.
This version also corrected a logic problem in computing each chip's statistics
by explicitly keeping track of NGOODPIX for each chip and using it for computing
the statistics for each chip.
Synphot
Data changes:
-
New wavecat tables were added for COS and WFC3.
-
The detectors.dat file was updated to
support WFC3 IR modes.
-
Two new environment variables, crcoscomp and
crwfc3comp, were added to provide access to the throughput files for COS and
WFC3.
-
A new environmental variable, crgridck04,
was added to provide access to the new Castelli and Kurucz (2004) atlas of
stellar atmosphere models. The new models can be used in the same way as the
older Kurucz models, and is recommended as a replacement for them. The
Pickles (1998) atlas of stellar spectra has also been made available for use
by synphot. Both new atlases are included in the synphot2.tar.z tarfile; it
can be downloaded and installed in the usual way from the synphot data
download page, ftp://ftp.stsci.edu/pub/software/stsdas/refdata/synphot/ .
Calcphot:
-
The efflam function was removed from this task after a bug was discovered in
the calculation.
-
The new function efflerg correctly calculates the effective wavelength in
energy units, according to the definition in the Koornneef et al 1986 paper.
It replaces the efflam function.
-
The new function efflphot was provided for backwards compatibility. It
replicates the incorrect calculation (performed with photon units) that was
performed by efflam. It may be used when direct comparisons with old
calculations of efflam are necessary, but should otherwise be avoided.
ANALYSIS
Drizzle
The help file for the drizzle task was modified to explain better the pixel
values being set in the context image.
PyDrizzle 6.0
The following changes were made:
-
Moving target support has been implemented.
-
PyDrizzle can now be run without doing a distortion correction.
-
The in_units parameter has been exposed to select the units of the
input image. This parameter defines the units of the input image. The
allowable values are 'counts' (default) and 'cps'.
-
The help file was correspondingly updated to describe the new
in_units parameter.
MultiDrizzle 3.0
-
The help file was updated to better explain the usefulness of the ERR opton
for the final_wht_type parameter.
-
The help file was updated to explain the updatewcs, final_units,
driz_cr_grow and driz_cr_ctegrow parameters.
-
A new feature was added to Multidrizzle: automatic generation of inverse
variance maps for weighting the final mosaic of ACS and WFPC2 data. If
the user specifies 'IVM' as the final_wht_type but does not supply
inverse variance maps, Multidrizzle will automatically generate these images
based upon the detector's characteristics and reference flatfield
file. This is an experimental feature that has not been fully
tested.
Several bugs were fixed, including:
-
Multidrizzle now properly passes the 'output' parameter to PyDrizzle for the
single file input case.
New support for using MultiDrizzle with WFPC2 data can also be found online at
http://www.stsci.edu/hst/wfpc2/analysis/drizzle.html
.
TOOLBOX
IMGTOOLS/MSTOOLS
-
New versions of MSARITH and MSSTATISTICS now support WFC3 as well as COS.
WFC3 IR data is treated like NICMOS data and WFC3 UV data is treated like
STIS/ACS/COS data.
-
Support for WFC3 was added to MSCOMBINE, MSDEL, MSJOIN, and MSSPLIT
PYTHON
A new shell command line task, print_asn, was added to print out the contents of
a table to standard out without having to explicitly load IRAF, PyRAF or Python.
Libraries
CVOS
The C interface function c_tbciga was added to the cvos interface
(XTABLES.def). For a table column containing array elements, this function
gets the dimension of the array and the length of each axis; this is only
relevant if the array dimension is greater than one. This is called by
calstis and calnica, and it makes more sense to include the function in the C
interface rather than defining interface functions in calstis and calnica.
HSTIO
The function putSingleNicmosGroupSect (and
supporting routines) were added to HSTIO.
ZZSETENV.DEF
-
Three new environmental variables were added
for synphot: crcompcos and crcompwfc3 for the new COS and WFC3 instruments,
and crgridck04 for the new ck04 atlas.
-
Only sets ref and tab variables if they
haven't already been set by the user before loading stsdas.