spacetelescope / rad

Nancy Grace Roman Space Telescope shared attributes for processing and archive
https://rad.readthedocs.io/
Other
5 stars 22 forks source link

Update photom schema #459

Open tddesjardins opened 1 month ago

tddesjardins commented 1 month ago

In the photom schema, we have under phot_table an entry for each optical element that currently contains the following:

I suggest we add to this the following fields (welcome feedback here):

One thing I have not figured out yet is how to store the additional zeroth-order throughput of the grism which we additionally have. Any suggestions for that are welcome. Maybe an optional field throughput_zero ?

schlafly commented 1 month ago

The Goddard throughput files are in effective area, which I find kind of nice. This is degenerate at some level with photmjsr, but all things being equal, I'd rather have the normalization in the throughput as well. Is there a reason not to include that?

Making sure I understand---the zeroth order grism is a ~direct image with weird-ish but fairly nominal PSF? Do higher grism orders come in as well at some very low amplitude?

At some level this is vaguely analogous to ghosts in direct imaging, which I feel like we usually do not include in the PSF or throughput curves, arguing that they are uncertain and small. In that context, one option is to not include that information. But I gather that the amplitudes are larger for the grism zeroth order data and we should include it.

I don't have a good idea there. I have a vague preference for not complicating the schema, and instead adding a new "filter" that is "grism_order_zero" that gets all of the information. It's unclear what we would do with that information in romancal, but at least the data would be present in the reference files.

stscijgbot-rstdms commented 1 month ago

This issue is tracked on JIRA as RAD-178.