Consider adding nonzero default pupil shear for coronagraphs based on ISIM CV measurements

[mperrin]

Issue by mperrin
Thursday Mar 16, 2017 at 21:41 GMT
Originally opened as mperrin/webbpsf#158

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From JWST-RPT-028027 (the ISIM CV pupil shear final report), the current best estimates for pupil alignments in ISIM are:
MIRI: -1.2% shift in V2, 1% in V3.
NIRCam: 0.2% in V2, -2% in V3 from PAR measurement; -0.1% in V2, 0.1% in V3 from PIL measurement. (See the above cited report for discussion of the discrepancies between the two measurement methods)

The NIRCam coronagraph Lyot masks are sized to accommodate misalignments and there should not be much effect on the contrast. For MIRI the Lyot masks are not undersized and the impact of misalignment is larger. We should consider updating the default setup for coronagraphic observations to take this into account.

Likewise we could also consider adding in the pupil rolls for each instrument. These are of order 0.6%, in some cases a bit larger.

[mperrin]

Comment by mperrin
Friday Apr 27, 2018 at 22:52 GMT

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This task has been folded into the plan for #204