search

desihub / desisurvey

Code for desi survey planning and implementation
BSD 3-Clause "New" or "Revised" License
2 stars 7 forks source link

Consider moving freeze_iers to desiutil #106

Closed weaverba137 closed 4 years ago

weaverba137 commented 4 years ago

freeze_iers() currently has two purposes:

  1. The normal purpose of preventing code on a compute node from being forced to download the IERS-A table.
  2. The extra, workaround purpose of preventing all code from downloading the IERS-A table from a server that is unavailable.

This creates a dependency on desisurvey for code that would not normally ever need that dependency. If freeze_iers() were moved to desiutil, this extra dependency would be unnecessary.

dkirkby commented 4 years ago

There is a third purpose, which was the original motivation and the reason it currently lives in desisurvey: ensure exactly reproducible coordinate transformations over the survey duration for the purpose of scheduling tiles in forecasts and operations.

weaverba137 commented 4 years ago

Good point, but that would not prevent us from moving the code to desiutil.

weaverba137 commented 4 years ago

In addition: from recent tests on desisim, it looks like freeze_iers() is not compatible with astropy 4.0. Make sure to test this if/when this moves to desiutil.