[fitsbits] ds9 DATASEC and mosaics of MEFs
Richard J. Mathar
mathar at mpia-hd.mpg.de
Mon Feb 24 14:24:11 EST 2014
I have a MEF file with 4 square images of a 4 detector array in a
2X2 mosaic geometry; some 167 pixels in the
cross in between, one 2D image per extension.
ds9 versions 6.2, 7.2 and 7.3b display them all in the same
"full" field if we load that FITS file with ds9 -mosaicimage *.fits.
However, the images are shown with the 2nd (lower right)
of the extensions/images at an incorrect offset position:
(3rd.) (4th...)
(....) (4th...)
(1st.) (2nd...)
(....) (2nd...)
I observe that once I disable the "DATASEC" button in the "Scale"
menue, the 2nd image moves more to the left underneath the 4th,
(3rd.) (4th...)
(....) (4th...)
(1st.) (2nd...)
(....) (2nd...)
as expected. Is this a known bug in DS9?
In the first HDU we have
XTENSION= 'IMAGE ' / IMAGE extension
BITPIX = 32 / number of bits per data pixel
NAXIS = 2 / number of data axes
NAXIS1 = 2048 / length of data axis 1
NAXIS2 = 2048 / length of data axis 2
PCOUNT = 0 / required keyword; must = 0
GCOUNT = 1 / required keyword; must = 1
EXTNAME = 'WIN1_1 '
HDUVERS = 1
DATASEC = '[1:2048,1:2048]' / [px] section of DETSIZE
TRIMSEC = '[5:2044,5:2044]' / [px] section of DETSIZE
RA = 269.582565 / [deg] R.A.: 17:58:19.8
DEC = 58.194737 / [deg] Dec.: +58:11:41
PIXSCALE= 0.45 / [arcsec/px]
CUNIT1 = 'deg ' / WCS units along axis 1
CUNIT2 = 'deg ' / WCS units along axis 2
CTYPE1 = 'RA---TAN' / WCS axis 1
CTYPE2 = 'DEC--TAN' / WCS axis 2
CRVAL1 = 269.582565317113 / [deg] RA in center
CRVAL2 = 58.1947373145248 / [deg] DEC in center
CD1_1 = -0. / [deg/px] WCS matrix diagonal
CD2_2 = 0. / [deg/px] WCS matrix diagonal
CD1_2 = 0.000124999996688631 / [deg/px] WCS matrix outer diagonal
CD2_1 = 0.000124999996688631 / [deg/px] WCS matrix outer diagonal
CRPIX1 = 2132.5 / [px] RA and DEC center along axis 1
CRPIX2 = 2132.5 / [px] RA and DEC center along axis 2
END
In the second HDU we have
XTENSION= 'IMAGE ' / IMAGE extension
BITPIX = 32 / number of bits per data pixel
NAXIS = 2 / number of data axes
NAXIS1 = 2048 / length of data axis 1
NAXIS2 = 2048 / length of data axis 2
PCOUNT = 0 / required keyword; must = 0
GCOUNT = 1 / required keyword; must = 1
EXTNAME = 'WIN2_1 '
HDUVERS = 1
DATASEC = '[2049:4096,1:2048]' / [px] section of DETSIZE
TRIMSEC = '[2053:4092,5:2044]' / [px] section of DETSIZE
RA = 269.582565 / [deg] R.A.: 17:58:19.8
DEC = 58.194737 / [deg] Dec.: +58:11:41
PIXSCALE= 0.45 / [arcsec/px]
CUNIT1 = 'deg ' / WCS units along axis 1
CUNIT2 = 'deg ' / WCS units along axis 2
CTYPE1 = 'RA---TAN' / WCS axis 1
CTYPE2 = 'DEC--TAN' / WCS axis 2
CRVAL1 = 269.582565317113 / [deg] RA in center
CRVAL2 = 58.1947373145248 / [deg] DEC in center
CD1_1 = -0. / [deg/px] WCS matrix diagonal
CD2_2 = 0. / [deg/px] WCS matrix diagonal
CD1_2 = 0.000124999996688631 / [deg/px] WCS matrix outer diagonal
CD2_1 = 0.000124999996688631 / [deg/px] WCS matrix outer diagonal
CRPIX1 = -81.5 / [px] RA and DEC center along axis 1
CRPIX2 = 2132.5 / [px] RA and DEC center along axis 2
END
In the third
XTENSION= 'IMAGE ' / IMAGE extension
BITPIX = 32 / number of bits per data pixel
NAXIS = 2 / number of data axes
NAXIS1 = 2048 / length of data axis 1
NAXIS2 = 2048 / length of data axis 2
PCOUNT = 0 / required keyword; must = 0
GCOUNT = 1 / required keyword; must = 1
EXTNAME = 'WIN3_1 '
HDUVERS = 1
DATASEC = '[1:2048,2049:4096]' / [px] section of DETSIZE
TRIMSEC = '[5:2044,2053:4092]' / [px] section of DETSIZE
RA = 269.582565 / [deg] R.A.: 17:58:19.8
DEC = 58.194737 / [deg] Dec.: +58:11:41
PIXSCALE= 0.45 / [arcsec/px]
CUNIT1 = 'deg ' / WCS units along axis 1
CUNIT2 = 'deg ' / WCS units along axis 2
CTYPE1 = 'RA---TAN' / WCS axis 1
CTYPE2 = 'DEC--TAN' / WCS axis 2
CRVAL1 = 269.582565317113 / [deg] RA in center
CRVAL2 = 58.1947373145248 / [deg] DEC in center
CD1_1 = -0. / [deg/px] WCS matrix diagonal
CD2_2 = 0. / [deg/px] WCS matrix diagonal
CD1_2 = 0.000124999996688631 / [deg/px] WCS matrix outer diagonal
CD2_1 = 0.000124999996688631 / [deg/px] WCS matrix outer diagonal
CRPIX1 = 2132.5 / [px] RA and DEC center along axis 1
CRPIX2 = -81.5 / [px] RA and DEC center along axis 2
END
and in the 4th
XTENSION= 'IMAGE ' / IMAGE extension
BITPIX = 32 / number of bits per data pixel
NAXIS = 2 / number of data axes
NAXIS1 = 2048 / length of data axis 1
NAXIS2 = 2048 / length of data axis 2
PCOUNT = 0 / required keyword; must = 0
GCOUNT = 1 / required keyword; must = 1
EXTNAME = 'WIN4_1 '
HDUVERS = 1
DATASEC = '[2049:4096,2049:4096]' / [px] section of DETSIZE
TRIMSEC = '[2053:4092,2053:4092]' / [px] section of DETSIZE
RA = 269.582565 / [deg] R.A.: 17:58:19.8
DEC = 58.194737 / [deg] Dec.: +58:11:41
PIXSCALE= 0.45 / [arcsec/px]
CUNIT1 = 'deg ' / WCS units along axis 1
CUNIT2 = 'deg ' / WCS units along axis 2
CTYPE1 = 'RA---TAN' / WCS axis 1
CTYPE2 = 'DEC--TAN' / WCS axis 2
CRVAL1 = 269.582565317113 / [deg] RA in center
CRVAL2 = 58.1947373145248 / [deg] DEC in center
CD1_1 = -0. / [deg/px] WCS matrix diagonal
CD2_2 = 0. / [deg/px] WCS matrix diagonal
CD1_2 = 0.000124999996688631 / [deg/px] WCS matrix outer diagonal
CD2_1 = 0.000124999996688631 / [deg/px] WCS matrix outer diagonal
CRPIX1 = -81.5 / [px] RA and DEC center along axis 1
CRPIX2 = -81.5 / [px] RA and DEC center along axis 2
END
so they all seem to use the same consistent coordinate system.
--
Richard J. Mathar phone (+49) (0) 6221 528 382
Max-Planck Institut f. Astronomie Fax (+49) (0) 6221 528 246
Germany URL http://www.mpia-hd.mpg.de/~mathar
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