Galactic Plate Carrée conversion?

svensk wrote on Aug 07, 2010

I have a full-sky plate carrée background map that I'd like to register to a subsection in a different projection (distorted tangential). Does anybody know of an IRAF command that could accomplish this?

wregister doesn't seem to do that, unless my headers are incorrect.

Thanks!

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Mike Fitzpatrick wrote on Aug 07, 2010

Please post the image headers for the respective images. IRAF should be able to handle the CAR projection (Galactic carree), however "distorted tangential" might refer to a number of things that aren't supported (i.e. are these something other than TNX or ZPX?).

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svensk wrote on Aug 07, 2010

Header for the galactic carrée image:

CRVAL1 = 180.000 /gal long (degrees) of ref pixel
CRPIX1 = 720.000 /ref pixel
CDELT1 = 0.250000 /delta gal long (degrees) for one pixel
CTYPE1 = 'GLON-CAR' /type of coord. system
CRVAL2 = 0.00000 /gal lat (degrees) of ref pixel
CRPIX2 = 360.000 /ref pixel
CDELT2 = 0.250000 /delta gal lat (degrees) for one pixel
CTYPE2 = 'GLAT-CAR' /type of coord. system

Header for the tangential image:

EQUINOX = 2000.0000 / Mean equinox
RADECSYS = 'ICRS ' / Astrometric system
CTYPE1 = 'RA---TAN' / WCS projection type for this axis
CUNIT1 = 'deg ' / Axis unit
CRVAL1 = 2.555131859E+02 / World coordinate on this axis
CRPIX1 = 9.080000000E+02 / Reference pixel on this axis
CD1_1 = -7.099391893E-03 / Linear projection matrix
CD1_2 = 0.000000000E+00 / Linear projection matrix
CTYPE2 = 'DEC--TAN' / WCS projection type for this axis
CUNIT2 = 'deg ' / Axis unit
CRVAL2 = -3.107378600E+01 / World coordinate on this axis
CRPIX2 = 6.675000000E+02 / Reference pixel on this axis
CD2_1 = 0.000000000E+00 / Linear projection matrix
CD2_2 = 7.099391893E-03 / Linear projection matrix

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Last post on Aug 07, 2010