Incorrect projection in v3b1 when CROTA keys present

[Jordatious]

An IDIA user has some mosaics created from CASA and WSClean images, which both include the deprecated CROTA FITS header keys. I've asked for a copy of these images to provide for @kswang1029.

carta.idia (v2.0.1) projects it fine, including with diagonal grid lines for the mosaic of the WSClean images. But carta-beta.idia (v3.0.0-beta.1b) incorrectly projects it without the diagonal grid lines. Spatially matching them doesn’t change it either.

[veggiesaurus]

example_images.zip

Here's an example of two images (C.fits and C_rot.fits). They are identical apart from the CROTA2 term. Both display correctly in DS9 and CARTA 2.0, but CARTA 3.0 beta-1 does not replace the CROTA2 entry with a CD matrix, and it does not seem to display correctly

[veggiesaurus]

Strangely enough, the CARTA backend now seems to replace CROTA2 with CROTA 🤷 not sure why.

I noticed that converting the file to HDF5 using fits2idia solves the issue (CROTA2 is no longer replaced with CROTA and the overlay renders correctly):

[kswang1029]

Strangely enough, the CARTA backend now seems to replace CROTA2 with CROTA 🤷 not sure why.

I noticed that converting the file to HDF5 using fits2idia solves the issue (CROTA2 is no longer replaced with CROTA and the overlay renders correctly):

Hmm so it is actually a backend issue?🤔

[veggiesaurus]

Hmm so it is actually a backend issue?

Looks like a casacore issue 🤔 Moving to carta-backend and assigning @pford