[AstroPy] Pywcs not reading transformation matrix correctly
Thu Jul 26 12:03:46 CDT 2012
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 ?
Astronomy Department, Caltech
More information about the AstroPy