iers.conf.iers_degraded_accuracy = "warn" also for IERS-A data?

[Heiko S.]

Hi, 

we use astropy for user scripts in a telescope control system, otherwise erfa in the CS code. 

A change of Linux distribution brought us an upgrade of astropy from 5.3.3 to 7.01. 

Our IERS data update strategy is to download IERS-A data regularly. So we aim for the highest precision. But if that fails (e.g. due to network access restrictions), and cached data is older than auto_max_age,  then we would like to get only warnings logged by astropy.

This worked fine in the old version of astropy, with setting iers.conf.iers_degraded_accuracy = "warn", which yielded  an IERSDegradedAccuracyWarning. 

It seems that with the inclusion of IERS-A data in astropy (commit 2da17a6c53), this config attribute is no longer applied to cached IERS-A data, but only to the IERS data that came already with the astropy installation. Instead of printing the warnings, astropy now fails with ValueError, which we don't want.

A possible workaround would be to set a very large auto_max_age, but then we don't even get the warnings that we actually like to see.

My question is, would it be possible to add a new config attribute that applies to cached IERS-A data, e.g. iers.conf.iers_degraded_accuracy_cached? Or to apply the existing attribute iers_degraded_accuracy to all IERS data sources (installation, previous download)? 

Or maybe I'm lacking imagination and one could get the old behavior back in a different way, without change in astropy?

Many thanks for any hint!

Heiko

[Timothy Pickering]

that data is now managed by the astropy-iers-data package. so to keep the data up to date, just use pip to upgrade that package regularly. for our systems, i run a daily cron job to do that.

tim

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[Marten van Kerkwijk]

Dear Heiko,

Great to hear that astropy is useful for your telescope control system!

I think you are right that the different sources of IERS A data should
be treated the same way, i.e., that the regression you are seeing should
be considered a bug that we should fix.

For that to happen, however, it would be easiest if you would raise a
github issue, so that we can have discussion just in that one place, and
have something to refer to for a possible PR. (Indeed, if you are
willing and able to write a PR that applies the existing
``iers_degraded_accuracy`` also to co-installed data, that would be very
welcome!)

All best wishes,

Marten

[Pey Lian Lim]

Hi, all. I opened https://github.com/astropy/astropy/issues/19823 for follow-up discussions. FYI.