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CALWF3 v2.1

CALWF3 v2.1 Release Notes

CALWF3 v2.1 was released for internal use at STScI on May 15, 2010 and was installed in the OPUS pipeline on Aug. 25, 2010 as part of OPUS build 2010.3. It was also released to the public on June 21, 2010 as part of STSDAS v3.12.

Relevant PRs for OPUS 2010.3

PR 65012 SAMPZERO keyword value not correct for IR subarray exposures

The SAMPZERO keyword in IR image headers gives the effective exposure time of the zero read (first sample taken after the detector reset). Previously it was populated with a static value of 2.911755 sec, which is only correct for full-frame IR readouts. WFC3 generic conversion has been updated to compute the correct value for all readout modes, including subarrays.

PR 65105 Perform NLINCORR for all IR images

In previous versions of calwf3, in which the IR processing performed NLINCORR after DARKCORR, NLINCORR was turned off when processing IR darks. Now that NLINCORR precedes DARKCORR it is performed for all IR expousres, including darks. This is accomplished by having WFC3 keyword rules set NLINCORR=PERFORM for all IR exposures.

PR 65349 Correct EXPTIME for short UVIS exposures

At the shortest commandable exposure times of 0.5 and 0.7 sec for the WFC3 UVIS channel, the actual shutter open time is somewhat shorter, corresponding to 0.480 and 0.695 sec, respectively. The headers of UVIS images taken using these commanded exposure times now have the EXPTIME keyword value updated to reflect the actual, rather than commanded, exposure time.

Relevant PRs for calwf3 v2.1

PR 64854 Reorder IR processing to swap DARKCORR and NLINCORR

In previous versions of calwf3 the IR non-linearity correction and saturation checking step (NLINCORR) was performed after dark subtraction (DARKCORR). The order of these steps has been reversed in calwf3 v2.1 so that NLINCORR is performed before DARKCORR, thus ensuring more accurate saturation checking and non-linearity correction of hot pixels before they are modified by dark subtraction.

PR 64941 Fix parsing of wf3rej 'crsigmas' parameter value

The wf3rej task parameter 'crsigmas' contains a list of CR rejection thresholds. The parsing of the list of values was crashing if there were embedded blanks within the string specified by the user. The parsing routine has been fixed to allow for embedded blank spaces.

PR 64963 Reorder UVIS wf32d and wf3rej processing steps

When the WF3REJ routine in CALWF3 is used to combine sets of images (e.g. CR-SPLIT's) it marks pixels in the input images detected to have CR hits by setting values in the DQ arrays of the input image files. When the EXPSCORR switch is set to PERFORM, which provides complete calibration of the individual input images, the DQ flags set by wf3rej should get carried over to the final calibrated images for the individual exposures. In previous versions of calwf3, however, the complete calibration of the individual exposures was occurring before wf3rej was executed and therefore the wf3rej CR flags did not appear in the individual calibrated images. The order of processing steps has been modified in calwf3 v2.1 so that wf3rej is performed before wf32d is executed on the individual exposures so that the CR flags now appear in the DQ arrays of the individual _flt output files.

PR 65151 Include calculation of MEANDARK in IR DARKCORR

The IR dark subtraction step (DARKCORR) was enhanced to compute the mean value of the dark current image subtracted from each readout of a MultiAccum exposure and store that value in the MEANDARK header keyword of the calibrated images.

Created 06/29/2010 MJD
Modified 09/08/2010 MJD