double check MIRI Lyot radius

[mperrin]

In clearing out my overflowing inbox I came across the following from last August, which we never followed up on. This is very low priority, I'm just making it an issue now so we remember to do it sometime - but not right now in the end of year rush.

Joseph:

Just realized we have two slightly different numbers for this in WebbPSF and the JWST Target Visibility Tool: https://github.com/spacetelescope/jwst_visibility/blob/master/jwst_visibility/gui.py#L980 (radius = 4.25 / 2 = 2.125 arcsec) https://github.com/spacetelescope/jwst_visibility/blob/master/jwst_visibility/gui.py#L980 (radius = 2.16 arcsec) I'm not sure we even know the radius to ~3 hundredths of an arcsec precision, but thought I'd check if either of you thought changes were needed. CCed Brendan because he was asking me about it.

Marshall:

The MIRI PASP paper on the coronagraph says 2.16” radius (http://arxiv.org/pdf/1508.02352v1.pdf at top of page 5) But my comments in the webbpsf source code say "#diameter is 4.25 (measured) 4.32 (spec) supposedly 6 lambda/D” which is consistent with the 2.125 number. However right now I can’t find the original source for that supposed measured value. We may want to check with Dean Hines and see if he knows, and if not I’ll send a query to Anthony Boccaletti.

[josePhoenix]

David Law might be the person to ask. I believe he was working on the MIRI SIAF inputs.

[mperrin]

oh come on, I explicitly put that disclaimer at the top of the issue so you would not spend any time on this now while dealing with your other deadlines! ;-)

[josePhoenix]

Haven't left the house yet, so it doesn't count!

[mperrin]

Issues migrated to https://github.com/spacetelescope/webbpsf/issues. Please see the copies in that repo from now on.