WCSAxes seem to be dependent on the unit handling of the WCS object

Hi All,

Thank you very much for all the work that you do and thank you in advance for any help. I’m suffering from a very odd issue and I was hoping someone may help. I’m using plot_coord to overplot a field of view on a solar image, but for one of my instruments it complains that I’m using the wrong units, which is not the case. Here is how I’m making the plot:

bottom_left_coord = SkyCoord(0*u.arcsec, 0*u.arcsec, frame=MWFmap.coordinate_frame)
top_right_coord = SkyCoord(300*u.arcsec, 300*u.arcsec, frame=MWFmap.coordinate_frame)
xZOOM = [bottom_left_coord.Tx, bottom_left_coord.Tx, top_right_coord.Tx, top_right_coord.Tx, bottom_left_coord.Tx]
yZOOM = [bottom_left_coord.Ty, top_right_coord.Ty, top_right_coord.Ty, bottom_left_coord.Ty, bottom_left_coord.Ty]
coord = SkyCoord(xZOOM, yZOOM, frame=MWFmap.coordinate_frame, unit = u.arcsec)`
ax1.plot_coord(coord,"w",linewidth = 0.5)

when I do the plot I get the error:

      529         if np.any(angles.value < lower) or np.any(angles.value > upper):
      530             raise ValueError("Latitude angle(s) must be within -90 deg <= angle <= 90 deg, "
--> 531                              "got {0}".format(angles.to(u.degree)))
    532
    533     def __setitem__(self, item, value):
ValueError: Latitude angle(s) must be within -90 deg <= angle <= 90 deg, got [  0. 300. 300.   0.   0.] deg

but printing coord, it is clearly not in degrees, but in arcseconds:

<SkyCoord (Helioprojective: obstime=1999-12-11T12:00:00.000, rsun=695700000.0 m, observer=<HeliographicStonyhurst Coordinate (obstime=1999-12-11T12:00:00.000): (lon, lat, radius) in (deg, deg, AU)
    (0., -0.40808519, 0.98470895)>): (Tx, Ty) in arcsec
    [(  0.,   0.), (  0., 300.), (300., 300.), (300.,   0.), (  0.,   0.)]>

Any idea what I may be doing wrong?

EDIT: Code formatting.

[amunozj]

Any suggestions @pllim, @Cadair ? Would this work?

“WCSAxes seem to be dependent on the unit handling of the WCS object”

[amunozj]

Ok Guys. After much hairpulling I think I found the problem. The header of this instrument’s fits file was missing two entries:

header[‘CTYPE1’] = ‘HPLN-TAN’
header[‘CTYPE2’] = ‘HPLT-TAN’