JP-3785: Add tangent plane transform corrections in NIRSpec spectral resampling

[hayescr]

Resolves JP-3785

Closes #8905

This PR fixes an issue with the NIRSpec spectral resampled WCS transforms from resampled pixels to a sky tangent projection. The transforms account for the additional extent of nodded slits along the tangent plane but the code currently only adds this correction for the sky direction that the slit is better aligned with. This PR adds the necessary corrections for both tangent plane dimensions.

Tasks

• request a review from someone specific, to avoid making the maintainers review every PR
• add a build milestone, i.e. Build 11.3 (use the latest build if not sure)
• Does this PR change user-facing code / API? (if not, label with no-changelog-entry-needed)
  • write news fragment(s) in changes/: echo "changed something" > changes/<PR#>.<changetype>.rst (see below for change types)
  • update or add relevant tests
  • update relevant docstrings and / or docs/ page
  • start a regression test and include a link to the running job (click here for instructions)
    • Do truth files need to be updated ("okified")?
      • after the reviewer has approved these changes, run okify_regtests to update the truth files
• if a JIRA ticket exists, make sure it is resolved properly

news fragment change types...

• changes/<PR#>.general.rst: infrastructure or miscellaneous change
• changes/<PR#>.docs.rst
• changes/<PR#>.stpipe.rst
• changes/<PR#>.datamodels.rst
• changes/<PR#>.scripts.rst
• changes/<PR#>.fits_generator.rst
• changes/<PR#>.set_telescope_pointing.rst
• changes/<PR#>.pipeline.rst

stage 1

• changes/<PR#>.group_scale.rst
• changes/<PR#>.dq_init.rst
• changes/<PR#>.emicorr.rst
• changes/<PR#>.saturation.rst
• changes/<PR#>.ipc.rst
• changes/<PR#>.firstframe.rst
• changes/<PR#>.lastframe.rst
• changes/<PR#>.reset.rst
• changes/<PR#>.superbias.rst
• changes/<PR#>.refpix.rst
• changes/<PR#>.linearity.rst
• changes/<PR#>.rscd.rst
• changes/<PR#>.persistence.rst
• changes/<PR#>.dark_current.rst
• changes/<PR#>.charge_migration.rst
• changes/<PR#>.jump.rst
• changes/<PR#>.clean_flicker_noise.rst
• changes/<PR#>.ramp_fitting.rst
• changes/<PR#>.gain_scale.rst

stage 2

• changes/<PR#>.assign_wcs.rst
• changes/<PR#>.badpix_selfcal.rst
• changes/<PR#>.msaflagopen.rst
• changes/<PR#>.nsclean.rst
• changes/<PR#>.imprint.rst
• changes/<PR#>.background.rst
• changes/<PR#>.extract_2d.rst
• changes/<PR#>.master_background.rst
• changes/<PR#>.wavecorr.rst
• changes/<PR#>.srctype.rst
• changes/<PR#>.straylight.rst
• changes/<PR#>.wfss_contam.rst
• changes/<PR#>.flatfield.rst
• changes/<PR#>.fringe.rst
• changes/<PR#>.pathloss.rst
• changes/<PR#>.barshadow.rst
• changes/<PR#>.photom.rst
• changes/<PR#>.pixel_replace.rst
• changes/<PR#>.resample_spec.rst
• changes/<PR#>.residual_fringe.rst
• changes/<PR#>.cube_build.rst
• changes/<PR#>.extract_1d.rst
• changes/<PR#>.resample.rst

stage 3

• changes/<PR#>.assign_mtwcs.rst
• changes/<PR#>.mrs_imatch.rst
• changes/<PR#>.tweakreg.rst
• changes/<PR#>.skymatch.rst
• changes/<PR#>.exp_to_source.rst
• changes/<PR#>.outlier_detection.rst
• changes/<PR#>.tso_photometry.rst
• changes/<PR#>.stack_refs.rst
• changes/<PR#>.align_refs.rst
• changes/<PR#>.klip.rst
• changes/<PR#>.spectral_leak.rst
• changes/<PR#>.source_catalog.rst
• changes/<PR#>.combine_1d.rst
• changes/<PR#>.ami.rst

other

• changes/<PR#>.wfs_combine.rst
• changes/<PR#>.white_light.rst
• changes/<PR#>.cube_skymatch.rst
• changes/<PR#>.engdb_tools.rst
• changes/<PR#>.guider_cds.rst

[melanieclarke]

One small suggestion for refactoring a helper function to avoid repeated calculations. Also, please add a change note - see instructions in the PR template, or let me know if you have difficulty with the new format.

[codecov]

Codecov Report

Attention: Patch coverage is 90.62500% with 3 lines in your changes missing coverage. Please review.

Project coverage is 61.96%. Comparing base (0938aaf) to head (7b4b18d).
Report is 464 commits behind head on main.

Files with missing lines	Patch %	Lines
jwst/resample/resample_spec.py	90.62%	3 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #8908      +/-   ##
==========================================
+ Coverage   61.86%   61.96%   +0.10%     
==========================================
  Files         377      377              
  Lines       38881    38793      -88     
==========================================
- Hits        24052    24037      -15     
+ Misses      14829    14756      -73     

☔ View full report in Codecov by Sentry.
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[melanieclarke]

Regression tests started here:
https://github.com/spacetelescope/RegressionTests/actions/runs/11469829363

[melanieclarke]

Regression test results look as expected for this change. There are changes to most NIRSpec MOS and FS products downstream of resampling.

The s2d changes are all changes to the WCS only, which shows up in diffs in the S_REGIONs. The x1d products show mostly fractional pixel changes to the extraction location (EXTRYSTR, EXTRYSTP) and corresponding minor changes to the extracted flux.

The MOS/FS test data set is the only one in the regtest suite that shows a significant change to the extraction location: test_nirspec_mos_fs_spec3[s000001354-x1d] shows a shift of about 1.5 pixels in extraction location. Looking at the corresponding s2d file, the new aperture location looks like an improvement over the old one: it centers the source better.

[melanieclarke]

LGTM! Thanks again for catching this and providing the fix.