[AstroPy] Pywcs not reading transformation matrix correctly
Oliver King
ogk at astro.caltech.edu
Thu Jul 26 13:15:22 EDT 2012
This might be the reason:
0.0.dev1119
I'll try updating to the latest version.
On Jul 26, 2012, at 10:10 AM, Thomas Robitaille wrote:
> Which version of Astropy are you using?
>
> import astropy
> print astropy.__version__
>
> 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?
>
> Thanks!
> Tom
>
> On 26 July 2012 19:03, Oliver King <ogk at astro.caltech.edu> 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.
>>
>> Cheers,
>> Oliver
>>
>> 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 ?
>>>
>>> Cheers
>>> JB
>>
>> ------
>> Oliver King
>> Astronomy Department, Caltech
>> +1-626-395-4197
>>
>> _______________________________________________
>> AstroPy mailing list
>> AstroPy at scipy.org
>> http://mail.scipy.org/mailman/listinfo/astropy
------
Oliver King
Astronomy Department, Caltech
+1-626-395-4197
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