STSDAS/Tables Version 3.9 Release Notes
19 November 2008
This release of STSDAS contains changes to NICMOS, ACS, STIS, WFPC/CALWP2,
COS, WFC3, CTOOLS, and the Dither packages.
The specific changes are detailed in the following sections.
TABLES
=======
No changes have been made to the Tables package since the last release.
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
were built with IRAF 2.14, except for Solaris, which were built with
IRAF 2.12.2a. IRAF is available from http://iraf.net.
HST_CALIB
=========
ACS
---
CALACS was updated to Version 5.0.2. This version includes:
- support for the change in gain settings which will occur as
a result of the repair mission.
- support for running CALACS on remote files (files not in the
current directory)
Bugs fixed include:
- eliminating compiler warnings under Solaris
- correctly keeping track of the number of exposures with non-zero
exposure time in the cosmic-ray rejection step
- setting the readnoise for each amp to the correct value in
the cosmic-ray rejection step
AXE
---
The aXe software package 1.7 was developed by the ACS group
of the ST-ECF.
This software has been moved into its own package in STSDAS; namely,
stsdas.hst_calib.slitless. There are now 2 packages that make up the
aXe distribution: axe and axesim.
Further information and documentation is available at the aXe pages:
http://www.stecf.org/software/slitless_software/axe/
COS
---
This release includes the IRAF interface to CALCOS Version 2.5.
The primary enhancements included in this version are:
- The coordinates for COS raw data have been changed. For both
detectors, the dispersion direction is now in the first axis and
increases to the right.
- When calibrating an association, a file with the product name
and "_jnk.fits" will be written. This is a copy of an input
"_spt.fits" file, created for use by the archive, and the user
should feel free to delete it.
NICMOS
------
This release contains CALNICA Version 4.4.0 and contains major changes
to several aspects of the calibration for NICMOS data including:
- Improving the algorithms in the up-the-ramp fitting, as
described in NICMOS ISR 2008-002, which improves the way
cosmic rays are rejected, as well as the way that count rates
and their errors are calculated.
- Correcting NICMOS data for the presence of image persistence
due to saturation by the bright Earth, as described in NICMOS
ISR 2008-001.
- Computing the temperature from the zero-th readout of each
exposure using the temp-from-bias algorithm
- Applying temperature dependent flat fields and dark images
using the temperature computed by the temp-from-bias algorithm
when appropriate
- Computing the temperature dependent photometric zero-point
correction based on the temperature computed by the temp-from-bias
algorithm when appropriate
Pipeline processing has been updated to apply all of these new
calibrations to produce significantly improved calibrated data.
New keywords have been added to NICMOS data in the pipeline to control
the operation of these new calibrations.
Questions about these new calibrations can be directed to the NICMOS
team at: help@stsci.edu
Instrument science reports documenting these changes can be found
online at:
http://www.stsci.edu/hst/nicmos/calibration/reffiles/documents/isrs
STIS
-----
This release still contains CALSTIS Version 2.26 (04-October-2007) and
represents the calibration to be used for the final reprocessing of all
STIS data taken prior to SM4. No changes were implemented for CALSTIS
since the last release.
WFPC2
-----
CALWP2 has been updated to Version 2.5.3 (Sep 4, 2008) in this release.
This version corrected the following bugs:
- Images where the bias value was greater than the maximum value
provided in the WF4TFILE no longer cause CALWP2 to crash.
- The CAL_VER keyword now gets updated during processing with CALWP2
WFC3
----
This release contains Version 1.1 of CALWF3.
Enhancements implemented in this version include:
- Converting calibrated UVIS and IR data to units of electrons
- Producing CRJ and dummy DRZ products for IR data, to remain
consistent with the UVIS processing products
- Updating the IR up-the-ramp fitting and cosmic-ray rejection
algorithms to utilize the improved methods implemented for NICMOS
- Updating the IR nlincorr step to use 3rd order correction
coefficients
- Updating the IR blevcorr step to use the robust mean of all
reference pixels for each readout
- Improving the sky computation used in UVIS image combination
and cosmic-ray rejection
- Updating the UVIS blevcorr step to reject outliers from the
parallel overscan fitting procedure
- Updating the IR noise calculation step to allow for
quadrant-dependent gain and readnoise values
Bug fixes include:
- Using correct IR gain and readnoise values in cosmic-ray rejection
- Proper handling of exptime=0 images by image combination/cosmic-ray
rejection step
Synphot
=======
There are no changes to the Synphot software in this release.
CTOOLS
=======
CHCALPAR
--------
Parameter sets were updated to include the new TFBCALC, BEPCORR and
other calibration switches for NICMOS data.
ANALYSIS
========
Tweakshifts
-----------
The new version of tweakshifts includes these enhancements:
- supports the use of distorted images on input
- computes shifts using the same center position as assumed by
geomap. These newly computed shifts can then be applied using
Multidrizzle without the need for iterations to get good alignment
for images with significant rotation.
- added 2 new parameters to allow an a priori guess for the
initial alignment of a pair of images.
PyDrizzle 6.3.0
===============
This version of PyDrizzle, along with the changes to 'makewcs' from the
pytools package, has been tested to accurately apply the distortion model
provided by the IDCTAB for ACS. Alignment of 2 images taken in separate
visits can now be made so that the errors in alignment have an RMS of
about +/- 0.05 pixels.
In addition, PyDrizzle calls 'makewcs' to update the header based on the
IDCTAB distortion model and updates the header to comply with the SIP
standard, including updating the CTYPE keywords to report 'RA---TAN-SIP'
and 'DEC--TAN-SIP'. Simply removing the '-SIP' from these values will
return the header to the straight tangent projection.
The following changes were made:
- Added support for WFC3
- Added support for time-dependent distortion for ACS/WFC data
- Added support for using SIP headers as input for the distortion
model, instead of using IDCTAB
- Updated use of DQ arrays for WFPC2 to support subarray image
where only a subset of the chips were read out
Additional details can be found in the release notes for the STScI_Python
package.
MultiDrizzle 3.2.1
==================
The following changes were made:
- Added support for UVIS and IR WFC3 data.
- Changed algorithms to use instrument's native units, rather
than always converting the data to units of electrons
- Improved the automatic IVM creation for NICMOS data.
- Updated the bunit keyword appropriately in the science extension
of the DRZ product.
- Run automatic IVM generation if user specifies it and no IVM
files available with the input image.
Additional details can be found in the release notes for the STScI_Python
package.
New support for using MultiDrizzle with WFPC2 data can also be found
online at http://www.stsci.edu/hst/wfpc2/analysis/drizzle.html.
