x1d.fits headers for the LRS should include PA_APER (and possibly more)

[stscijgbot-jp]

Issue JP-3844 was created on JIRA by Greg Sloan:

The x1d.fits files have headers without a critical piece of information for a long-slit spectrum: the PA_APER keyword: the principal axis of the slit. That information appears in the headers of the s2d.fits files in both Level 2 and 3, in the JWST ephemeris info section, but not the x1d.fits files for either level. Some of the other ephemeris information could probably also be carried over as well.

[stscijgbot-jp]

Comment by David Law on JIRA:

Note that PA_APER will be the position angle of the primary science aperture, so I believe in the case of LRS that PA_APER=0 would correspond to an E-W slit orientation.  Regardless of conventions, I agree this would be a useful piece of information to propagate; looks like we currently pass SLIT_RA and SLIT_DEC.  There may be some complications for multi-slit data that need to be worked through, as would be what to do when multiple different exposures have different PA.