[bug #58974] WCS conversion not reasonable on processed TPV data

[Mohammad Akhlaghi]

Update of bug #58974 (project gnuastro):

                  Status:             In Progress => Fixed                  
             Open/Closed:                    Open => Closed                 

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Follow-up Comment #1:

This bug has been fixed and merged into Gnuastro as Commit d3deff2954
<https://git.savannah.gnu.org/cgit/gnuastro.git/commit/?id=d3deff2954>. 

The same header now looks like this. I added a comment for the users who may
be use to having CDELT in Gnuastro's outputs, but also for ourselves in a few
years when WCSLIB 7.4 becomes very widely used, we can consider if we want to
keep this feature or not.


                      / World Coordinate System (WCS)                         
 
WCSAXES =                    2 / Number of coordinate axes                    
 
CRPIX1  =        1763.09429932 / Pixel coordinate of reference point          
 
CRPIX2  =         612.79893494 / Pixel coordinate of reference point          
 
CD1_1   = -1.25668483396501E-05 / Coordinate transformation matrix element    
 
CD1_2   = 7.88013645775204E-04 / Coordinate transformation matrix element     
 
CD2_1   = -7.88003754261799E-04 / Coordinate transformation matrix element    
 
CD2_2   = -1.25084009319101E-05 / Coordinate transformation matrix element    
 
CUNIT1  = 'deg'                / Units of coordinate increment and value      
 
CUNIT2  = 'deg'                / Units of coordinate increment and value      
 
CTYPE1  = 'RA---TPV'           / TAN (gnomonic) projection + distortions      
 
CTYPE2  = 'DEC--TPV'           / TAN (gnomonic) projection + distortions      
 
CRVAL1  =       113.3064285324 / [deg] Coordinate value at reference point    
 
CRVAL2  =       31.87889767116 / [deg] Coordinate value at reference point    
 
LONPOLE =                180.0 / [deg] Native longitude of celestial pole     
 
LATPOLE =        31.8788976712 / [deg] Native latitude of celestial pole      
 
MJDREF  =                  0.0 / [d] MJD of fiducial time                     
 
RADESYS = 'ICRS'               / Equatorial coordinate system                 
 
PV1_0   =   9.714784609182E-05 / TPV coefficient: 1                           
 
PV1_1   =   9.999868977236E-01 / TPV coefficient: x                           
 
PV1_2   =  -8.842015406255E-06 / TPV coefficient: y                           
 
PV1_4   =   1.822783853090E-04 / TPV coefficient: xx                          
 
PV1_5   =   1.365776728868E-04 / TPV coefficient: xy                          
 
PV1_6   =   2.257022520459E-05 / TPV coefficient: yy                          
 
PV1_7   =   1.920222380359E-04 / TPV coefficient: xxx                         
 
PV1_8   =  -3.830056501464E-05 / TPV coefficient: xxy                         
 
PV1_9   =  -1.347022772508E-04 / TPV coefficient: xyy                         
 
PV1_10  =  -2.471225520868E-05 / TPV coefficient: yyy                         
 
PV2_0   =   4.672062523823E-04 / TPV coefficient: 1                           
 
PV2_1   =   1.000878428319E+00 / TPV coefficient: y                           
 
PV2_2   =  -4.973468945505E-04 / TPV coefficient: x                           
 
PV2_4   =  -1.411294363997E-04 / TPV coefficient: yy                          
 
PV2_5   =   7.439750263035E-04 / TPV coefficient: yx                          
 
PV2_6   =  -1.224454154415E-03 / TPV coefficient: xx                          
 
PV2_7   =  -7.014289760875E-04 / TPV coefficient: yyy                         
 
PV2_8   =   3.351859178423E-04 / TPV coefficient: yyx                         
 
PV2_9   =  -4.470842932692E-04 / TPV coefficient: yxx                         
 
PV2_10  =   9.945076014402E-04 / TPV coefficient: xxx                         
 
COMMENT The CD matrix is used instead of the PC+CDELT due to conflicts with
TPV 
COMMENT distortion in WCSLIB 7.3 (released on 2020/06/03) and ealier. By
default
COMMENT  Gnuastro will write PC+CDELT matrices because the rotation (PC) and
pix
COMMENT el-scale (CDELT) are separate; providing more physically relevant
metada
COMMENT ta for human readers (PC+CDELT is also the default format of WCSLIB). 



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