[AstroPy] Pywcs not reading transformation matrix correctly
Thu Jul 26 12:10:07 CDT 2012
Which version of Astropy are you using?
I'm using the latest developer version, and it seems to be working:
CD_11 CD_12: -7.7588993045300006e-05 4.5042903792000001e-07
CD_21 CD_22: -3.9690360471000002e-07 -7.7631469153300006e-05
CRVAL : 343.48506545599997 16.146689138399999
CRPIX : 1094.26737976 1037.5606839899999
NAXIS : 0.0 0.0
If you are using v0.1, could you try updating to the latest git
version to see if it was fixed?
On 26 July 2012 19:03, Oliver King <email@example.com> wrote:
> Hi JB,
> The WCS does not have a RADECSYS keyword; the CTYPE is TAN-SIP. Here are all the WCS parameters (excluding the polynomial coefficients). This is an image which has had a WCS attached by the astrometry.net software.
> CTYPE1 = 'RA---TAN-SIP' / TAN (gnomic) projection + SIP distortions
> CTYPE2 = 'DEC--TAN-SIP' / TAN (gnomic) projection + SIP distortions
> WCSAXES = 2 / no comment
> EQUINOX = 2000.0 / Equatorial coordinates definition (yr)
> LONPOLE = 180.0 / no comment
> LATPOLE = 0.0 / no comment
> CRVAL1 = 343.485065456 / RA of reference point
> CRVAL2 = 16.1466891384 / DEC of reference point
> CRPIX1 = 1094.26737976 / X reference pixel
> CRPIX2 = 1037.56068399 / Y reference pixel
> CUNIT1 = 'deg ' / X pixel scale units
> CUNIT2 = 'deg ' / Y pixel scale units
> CD1_1 = -7.75889930453E-05 / Transformation matrix
> CD1_2 = 4.5042903792E-07 / no comment
> CD2_1 = -3.9690360471E-07 / no comment
> CD2_2 = -7.76314691533E-05 / no comment
> IMAGEW = 2048 / Image width, in pixels.
> IMAGEH = 2048 / Image height, in pixels.
> On Jul 26, 2012, at 9:58 AM, Jean-Baptiste Marquette wrote:
>> Hi Oliver,
>>> Is this a known bug? Is there a workaround or do I need to manually edit my FITS file headers?
>> What are your CTYPEn and RADECSYS ?
> Oliver King
> Astronomy Department, Caltech
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