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Astronomy Image Processing Mathematica Import and Export

Problem with .FITS files

Posted 11 years ago

Hi, I cannot open some .fits files from the LASCO instrument of SOHO observatory. http://lasco-www.nrl.navy.mil/index.php?p=content/database http://sharpp.nrl.navy.mil/cgi-bin/swdbi/lasco/images/form For some fits (not for all) the command Import[filename.fits] prints $Failed, but I can open the same fits with other applications (this means that the files are not damaged). Is this a bug or am I doing something wrong? Thank you.

POSTED BY: Pavlos Gaintatzis

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Posted 9 years ago

As of version 11.0.0 (August 2016) FITS files with a data field in a bit-array format are not being supported in Mathematica. This remains quite unfortunate. The data types of a FITS file are sometimes described in the header unit. Try using Import["fileName.fits", "Metadata"] to explore your file if Import["fileName.fits", "RawData"] fails. Attached are two FITS files from the Fermi LAT Gamma Ray space telescope. The data tables in the first (Pass7) file loads while one of the data tables in the second (Pass8) file fails because it contains two columns of data in a 32x bit field format. Attachments:

POSTED BY: Michael Goldstein

Posted 11 years ago

I don't know much about FITS, but I thought it will be useful if I post this (and help avoid some confusion): FITS is a rather complex format that can store different kinds of data in various ways. Mathematica only supports certain kinds of FITS files. It is likely that your files are not damaged, but Mathematica simply doesn't support this particular kind of FITS file. I remember trying to read in some FITS files once, and after discovering this, I gave up on doing it directly with Mathematica. You might convert it to an easier to read format with some other application, and then read the other format into Mathematica. This is not a bug, and you're likely not doing anything wrong. Mathematica simply doesn't support FITS fully, probably because of the complexities and the generality of the format. (I did not actually download your files, I'm just sharing my previous experiences with FITS.)

POSTED BY: Szabolcs Horvát

Posted 11 years ago

OK, I know that. Im sending you two .fits files (A and B ) from LASCO: https://www.dropbox.com/s/ltu1f0twu3gx5k1/LASCO_FITS.rar I can open the file B.fts but I can't import the file A.fts. The two images captured by the same camera (C2), the A.fts is a decompressed image (Level 0.5) and the B.fts is a calibrated image (Level 1).