Calstis Version 2.11 was installed in the OTFR pipeline on September 13, 2001. It is available for download in the new STSDAS release, Version 5.11, which can be found at the STSDAS Advisories page.

Below we give more details on changes that are likely to be noticed by users in their data.

For STIS echelle data, the spectral orders near the top and bottom of the image are shifted left or right (in opposite directions) by up to a few pixels, with respect to the positions computed from the dispersion relation. The amount of shift depends on the global offset in the Y direction of the image on the detector.

1-D extraction and 2-D rectification can now be performed for prism data. Changes were made to the wavecal processing and to the interpretation of the dispersion coefficients for prism data. The current dispersion (dsp) reference table for the NUV MAMA includes entries for the prism for both tilts.

When extracting a first order spectrum, calstis will now stop processing if the cross correlation to locate the spectrum in the input image fails. In the past, the spectrum was extracted at a default location, resulting in no useful data. Although a warning was written to the trailer file, there was no information in the output table to indicate the problem. Now the output table will not be created, and calstis will print an error message and proceed immediately to the next imset (if there is one) in the input file.