[bug #63815] Warp removes essential keys from header

[Jean-Luc Margot]

URL:
  <https://savannah.gnu.org/bugs/?63815>

                 Summary: Warp removes essential keys from header
                 Project: GNU Astronomy Utilities
               Submitter: jlm
               Submitted: Sat 18 Feb 2023 04:27:46 AM UTC
                Category: Warp
                Severity: 3 - Normal
              Item Group: Input/Output
                  Status: None
                 Privacy: Public
             Assigned to: None
             Open/Closed: Open
         Discussion Lock: Any


    _______________________________________________________

Follow-up Comments:


-------------------------------------------------------
Date: Sat 18 Feb 2023 04:27:46 AM UTC By: Jean-Luc Margot <jlm>
Take a fits file 'original.fits'.  Warp it:

astwarp --hdu=1 --rotate=0 -o warped.fits original.fits

(I read the documentation and did not find an option to preserve the header
keys not affected by the warp operation)

Compare headers of original and warped images:

imhead original.fits > original.txt
imhead warped.fits > warped.txt

Note how the header has been reduced from 471 lines to 152 lines
wc original.txt warped.txt 
  471  original.txt
  152  warped.txt

Note how some essential keys/values are missing from the warped file 

grep MJD original.txt warped.txt
original.txt:MJD_OBS =       55360.51456292 / [days] Obs. midpoint Modified
Julian Day
warped.txt:MJDREF  =                  0.0 / [d] MJD of fiducial time

grep UTC warped.txt returns 0 values, whereas the original file had 5 UTC
values

Thank you.







    _______________________________________________________

Reply to this item at:

  <https://savannah.gnu.org/bugs/?63815>

_______________________________________________
Message sent via Savannah
https://savannah.gnu.org/