resample_spec & cube_build need option to use internal coordinates for NIRSpec internal lamp processing

[stscijgbot-jp]

Issue JP-1427 was created on JIRA by James Muzerolle:

The specifications for NIRSpec internal lamp processing (JP-473) include the generation of 1D spectra in the case of LINE or REF lamp calibrations or science autowavecal exposures.  Currently, resample_spec and cube_build, which must be run prior to 1D extraction (for MOS/FS and IFU data, respectively), are set up to use only sky coordinates for the spatial dimensions.  However, the WCS for internal lamp data does not include sky coordinates since the light path does not extend past the filter wheel.  So, in order to run resample_spec/cube_build and extract_1d for these cases, the algorithms need to be modified to use alternate spatial coordinates.

For cube_build, the ideal option would be to use spatial coordinates in the slicer plane.  I think this is  equivalent to the MIRI alpha-beta space (as mentioned in JP-1013).  Ideally, we would like to be able to generate a 1D spectrum per IFU slice, so this option would make that easier to do.

For resample_spec, any coordinate(s) in the MSA aperture plane would suffice.  Technically, we don't need both orthogonal directions to be included since the apertures are uniformly illuminated, so for example resampling to slit_y vs wavelength space might be the cleanest option.  However, if it would be easier to keep two spatial coordinates, the MSA_X and MSA_Y values could be used instead.

1D spectral products for LINE/REF lamp exposures are required for calibration, and will need to be validated using Commissioning observations prior to the start of science observations; thus, this work is critical for Commissioning.

[stscijgbot-jp]

Comment by Anton Koekemoer on JIRA:

This was discussed in JWST Cal WG meeting 2020-08-25 and is accepted for the pipeline version expected for offline use during commissioning, ie post-B7.6, with the additional expectation that this needs to be in the operational DMS pipeline by the start of science operations, since this is also needed for autowavecals for science data that will be processing through the pipeline.
{task:id=607}Next steps: James Muzerolle  will iterate with Jane Morrison  and David Law  and others as needed from SCSB and/or INS, for the implementation of this for MOS and fixed slit mode, for NIRSpec.{task}

[stscijgbot-jp]

Comment by Howard Bushouse on JIRA:

resample_spec step updated to use MSA frame for lamp exposures in #5484 This completes the updates for both cube_build and resample_spec.

[stscijgbot-jp]

Comment by Misty Cracraft on JIRA:

James Muzerolle  Has this been tested? Tagging Jane Morrison and David Law  for updates as well.

[stscijgbot-jp]

Comment by James Muzerolle on JIRA:

Tested using ground internal lamp data, all modes.